In my stupid ahh opinion: The Wandenreich invasion should have been Wild Hunt (from the Witcher) levels of threatening and it should have been an invasion on *ALL* of three worlds. And I disliked the way the Sternritters and Yhwach were portrayed in the first invasion of Soul Society. The "stealing Bankai" and "allergic to hollow powers" didn't sit well with me after reading the criticisms and made them look weak.
Woulda been cool to see the first Substitute Soul Reaper, Kugo Ginjo to take out Jugram with Shukoro(Tsukishima if you didn't get it) and some Espada's(Grimmjow and Zommari) help together(both Bleach and Naruto have their fair share of wasted potentials, which is why so many ppl make rewrites about them).
Your opinion isn’t stupid, it’s a valid criticism that I mostly agree with.
I agree that the Wandenreich’s invasion should have been on all three worlds and it should’ve been an all-in attack. You can’t present readers with an end of the world scenario and exclude two of the worlds. Kubo didn’t properly utilize the World of the Living and Hueco Mundo.
The Wandenreich initially neutralized Hueco Mundo and enslaved the arrancars but Kubo completely abandoned that plot line. The HM issue is pushed off to the novels and left unresolved in the manga making the story seem and feel incomplete.
As for the World of the Living, it was completely left alone. The absolute worst thing that happened to the World of the Living was some mild earthquakes after the Soul King died. Kubo could’ve deployed Ichigo’s human gang to fight small battles in the World of the Living but instead he left them on standby for the entire arc.
Another add-on to this issue: The war’s location was ever-changing. Rather than having the war rage on all of the worlds or keeping it strictly in one place, the war changed from HM, SS, then the Soul Palace. Which, in my personal opinion, was a bad choice.
There was never a valid enough reason to let a bunch of nobodies to go up to the Soul Palace. The Soul Palace should’ve remained as an ambiguous place that was near impossible to infiltrate, and even if entry was granted the air itself would be too dense and rich in reiatsu for regular soul reapers and humans to handle. But instead, everyone and their mother went up there, effectively making the Soul Realm lose all of the divinity and mystic it had going for it. (And if Kubo needed everyone to go up to the Soul Realm, there should’ve been side effects on the Soul Reapers bodies and reiatsu, as well as consequences for entering.)
And regarding the Wandenreich’s first invasion, I actually disagree that it was the worst part of the war. I am personally of the opinion that the first attack on the Soul Society was the best part of the TYBW.
The element of surprise and the preparation that went into it made it more interesting than the other parts of the war.
Ambushing the Soul Reapers
All of the listed are cowardly acts but they also showed the Quincy’s desperation to win and their ability to push past their pride. And that directly opposed the Soul Reapers way of battle. The Soul Reapers often faced defeat because they let their pride get in the way. (E.g. Soi Fon sidelining her lieutenant against Espada 2, Squad 11’s refusal to help each other in battle) So it was refreshing to see a different method of battle and how it would play out.
My personal problem with the first invasion is that the Bankai stealing tool was interesting enough but it also falls under the category of plot-convenient one-time use tools with minimal explanation that keep popping up in TYBW.
And about Uryuu and Jugram: while I think Uryuu was Jugram’s perfect opponent, I agree Ginjo deserved a proper fight. Dude is a Soul King candidate, it would’ve made sense if he had a bigger role in, what was later named, the Soul King Protection War. Ginjo is completely under-utilized and does legit nothing during the war.
And the Espada also deserved bigger roles. They are walking-talking Quincy poison and their world got colonized, it makes no sense that they did nothing of worth during the war.
I’ll always say this: TYBW’s biggest crime is that in a supposedly large-scale conflict, everyone does a bunch of nothing.