Interesting concept. Not sure I can agree with the premise of people enjoying things less overall, but there's lots of implications here that are definitely worth mulling over.
My gut instinct on this is that there are two primary modalities to enjoyment, and people can both switch between them or get stuck in one for such a long time that they might look incapable of switching. And, well... they might be incapable!
Like many of our behaviors, the modality may be dictated by involuntary circumstances— stress, mental health, age, education, social circumstances, job type. And I think we can agree that the modality of surface-level enjoyment is the "easier" process of the two. So it may not be healthy to chronically stay in the surface-level enjoyment, just like it's not healthy to never read books and get all your information off social media, but for many, the deeper-read modality may also be outside of their current capacity to do more difficult things.
Similarly, if we agree that it's the more intensive of the two, I'd propose that it's actually healthy to take breaks from the deeper-read enjoyment too bc all of our mental faculties need breaks or varied usage for a more rested brain and more adaptive thinking. Like OP said, "not everything is meant to be high art," but I'd like to go a step further and invoke "slow down and smell the roses" as an argument for the benefits of using both modalities regularly, even if you have to develop this skill. You should be able to "slow down" and process an encounter with new ideas to give yourself the chance to use deeper-read modality but also be able to "smell the roses" and take a break from describing or composing poetry about roses to... just... smell... using surface-level modality.
A point of contention over this can definitely arise in social settings (see: fandom) where likely everyone has a different balance of how much time they spend in each modality. For my comparison, I'll set aside people who are really taking things just one day at a time right now and have zero energy or patience for deeper-read enjoyment while they try to recover.
Let's say that at a party, Person A, who is naturally disposed to using surface-level enjoyment more often, finds themself sitting next to Person B, who is naturally disposed to using deeper-read enjoyment more often. After trying and failing for an hour to enjoy each other's company, they finally go their separate ways to find less frustrating people to talk with. Person A is frustrated that their simple pleasures are not being affirmed, that each topic is being deprived of its luster by taking it seriously at a party without any room to relax and let the conversation be frivolous. Person B is frustrated that the value of their analysis is not being affirmed, that each topic is being abandoned as soon as it is brought up without any room to discuss possible implications.
It's not impossible for Person A and Person B to coexist and even become friends someday, but in order for a friendship to develop, they'd probably need to find topics on which they synchronize modalities. Perhaps after a few more encounters at these shindigs, they finally discover that there's a movie they both prefer to enjoy with a deeper-read, but they also both follow a subreddit with dumb posts that they want to cackle about using surface-level engagement.
Alternatively, they may meet again outside of a party, perhaps running into each other at a museum, and Person B will notice that Person A is using a lot more deeper-read modality in the new context. Perhaps Person B will really like spending time with Person A in museums, enough to try slipping into surface-level modality at the next party so they can stay synchronized. Similarly, many people participate in fandom as their primary surface-level enjoyment, while others show up almost exclusively for deeper-read enjoyment, and we can't really guess without getting to know someone how they enjoy things offline.
I didn't want to dig through responses, but on my brief glance, I saw mention of turbulent disagreement, and that his ideas about enjoyment have brought OP a lot of grief. Not to excuse but merely contemplate, a knee-jerk defensiveness of being jostled to expend more energy makes sense; asking to take on higher cognitive loads is similar to how many people are (sometimes extremely) touchy when reminded they should be exercising for the benefit of their own mobility. Generally, there's an invisible reason for that touchiness (disability, mental health, they get plenty of physical activity during their day job and need rest, wrong place wrong time for health advice, etc).
So all that said, I meant what I said above, that I propose these modalities are skills, in the sense that someone who struggles with over-analysis might benefit from developing mindfulness skills and learning how to enjoy the simple here and now. It may not be easy or fun, but it has its benefits.
Similarly, I agree with OP that slowly building a higher capacity for deeper-read enjoyment can be very valuable if a person finds that they've fallen into a habit of surface-level pleasure only. Outside the context of fandom, embracing some discomfort to unlock a more frequent deeper-read enjoyment could bring benefits to a person's mental health, relationships, ability to focus, and creative output, while also reinforcing the related skill of critical thinking.
The tricky part here is that we can't know, from the outside looking in, and especially not through screens, keyboards, and many miles of internet cable, whether such a self-improvement intervention is appropriate for everyone who we only ever see enjoying things at the surface-level during their fandom activities.
