I don't quite agree that a "game wasn't strong enough" if there can be satisfaction from watching a stream of it, but I do see what he's saying.
The gameplay, not the story, takes precedent, from this perspective. For example, I love the characters and story in Kingdom Hearts and Devil May Cry. But I still say Rival Schools is my favorite game because I remember how that gameplay felt so good to me, specifically. But I still cry, watching Kingdom Hearts cutscenes, even for the games in the franchise that I haven't yet played.
I don't think there's necessarily always "ludo narrative dissonance" (as Hideo Kojima discussed) when a game can be enjoyed, by just watching, without playing. I think lots of games properly integrate gameplay, to a level of conveying feelings about the narrative, and yet there's still something for non-player audiences to enjoy. It's just that actual players will experience more layers of the narrative, that simply will escape mere watchers.
For example, you can watch all the cutscenes of Rival Schools. But the exhilaration from the experience of the game comes less from the story and more from the fighting gameplay. Fighting games especially, have narratives and characters that function more to support the gameplay, rather than the other way around.
But also, even a fighting game can have a great story, like Guilty Gear, that can be enjoyed even separately from gameplay. But also, anyone who plays Guilty Gear will get the added bonus layer of the experience of the characters/story that can only be felt thru gameplay.
Like, I have extra attachmemt to Ky Kiske because his gameplay gave me an extra experience of his character, in addition to the cutscenes. His gameplay made me feel how focused and careful, yet mentally quick he is, about battle. There's a reason that Ky "mains" are stereotyped as constantly honing themselves towards no holes in our defenses and to become relentless attackers. His gameplay style enables that, and not using his quickness, agility, and range would feel wasteful. His gameplay enables so many options, at any moment, that it feels wasteful to not use, and that subconsciously encourages Ky players to take advantage, and therefore, get into the mindset of a character that is constantly thinking of the next move.
Ky gameplay made me feel the frustration of finally beating Sol, and wondering why he "suddenly went easy on me", after so many rounds of beating my ass and forcing me to be constantly at my peak. What else was i supposed to think??? ...Then I had to take a breath in real life and realize that was stupid. Ky was being stupid. We were both being stupid. Because of course you gradually get accustomed to a sub boss fight and eventually can beat it. But the gameplay made me FEEL thst frustration, that split second of paranoia, that Sol was just being condescending or lazy. Because, when you're constantly pushed on edge, all the time, by a strong opponent like Sol, and grow so accustomed to that edge that you grow to love it, that pressure suddenly being taken away feels wrong. "He must be condescending to me. He must be being lazy. How else could i have won after he's been so relentlessly difficult to fight without a second of rest? It's insulting. How dare he not take this seriously." And secretly, "How dare he deprive me of this exhilaration of constantly pushing me beyond my edge." These are all things that Ky also said in cutscenes. But feeling it myself, thru gameplay, was an enhanced additional layer of that characterization.
These are characterizations that may gradually be grasped soley thru cutscenes. But feeling the gameplay myself, enhanced it.
We also can't ignore the precedent of sports fandom. Humans have proven for years, that they will find excitement by being invested in watching someone else play. A football fan may never play football themselves, but they can love and be invested in football enough, to riot snd cry when their favorite team wins. My elderly mother loves boxing. She has never practiced boxing herself. Are football and boxing badly designed games, because they can be enjoyed by spectators who never play themselves? Of course not. The game is designed well for the players. But there must be a completely separate phenomenon happening, alongside that game.
I think humans can become invested into almost anything. We're social animals, who have evolved to benefit from becoming easily emotionally attached and emotionally invested into others and their experiences. That's sympathy and empathy. Both of which are essential to social creatures. And humans' advantages have always included working within a group. We have no claws, yet when 1 human is threatened by an animal, we can make that animal population go extinct, because we work as a group. That's why humans have survived thus long, by evolving to be social or have the traits that enable sociability, like empathy. We can become invested in anything. It's why pareidolia exists. It's why "cute aggression" happens. Humans can empathize and become so very invested in something that is happening to someone else and not just our first-hand experience.
So yeah... I think it's natural to enjoy a game, just as a spectator. But if you actually play the game yourself, then you get an added layer of enhanced experience. You feel more of the experience that the authors intend to convey. And more visceral emotions are conveyed, more intensely thru the gameplay.
But I do agree that those of us, who only watch a game, are receiving only a partial experience of the feelings that the game developers/authors wanted to convey. We may be able to comment on story analysis and favoriting a character. But we can only talk second-hand about the experience of the gameplay, as actual players have described it to us. We're not "stream-only players". We're not even "players". We're just fans. We're just audience spectators. We can buy merch, get excited, fangirl over characters, write fanfics, analyze power scaling, characters, and story...But I do admit, that despite all we can glean from someone else's playthrough stream of a game, we are only receiving partial experience. Personally, I think it's still a good experience. But I acknowledge that it would be a much better, more enhanced, more layered experience, if I felt first-hand, all the things that the game developers wanted to convey.
But man, am I glad for my ability to enjoy watching others play! Have you ever been part of a big group of cousins or friends, all waiting for your turn to play? But there are so many of you, it takes forever to get to your turn? You learn very quickly to enjoy just being a spectator. Especially when it gets to your turn or you're playing by yourself, and you suck, so you can't advance further in the game or story. Sometimes you can only enjoy a game by watching others play.
Also, especially in this economy, games are expensive!