This would be all fine and well if their official app weren't garbage. They do everything in their power to push you to the mobile app, but they seemingly haven't improved it since its inception.
It's not garbage. I've used it for years. It's fine. Try not being dramatic online / feeding into the narrative that so and so app is garbage or not / parroting other things people say / being picky.
It may have been a "fine" experience for you, but that does not give you the right to attack ad-hominem others who did not have the same experience. If you want to attack their position, attack their arguments. Show us how the official app is at least barely usable. Or how navigation and search aren't like children's toys. Or how the iOS app actually got better instead of worse after Reddit Inc. bought it. Or how the Android app got any of the features the iOS app deigned to retain post-acquisition. Or how the YouTube-esque ad-pushing makes for a good UX. Or how comment scores and user karma aren't totally infuriating to look for.
If you can't argue on merits, you cannot participate in discussions of any kind except primary school 'no u'.
Needless to say, there are many people (such as myself) who enjoy what Reddit is/was, and would prefer it to stay that way. Emphasis was not placed on posts themselves, but rather the discussion surrounding the posts. This design goal is clear in the layout of the old.reddit.com layout, which is optimized for information density, back and forth conversation, and parallel conversational threads (quite unique compared with modern social media apps).
So long as third-party apps and the old.reddit front-end exist, Reddit can still exist as a discussion-board focused site that (in the minds of some users) keeps the site unique. With the death of third-party apps, we are forced into the vision that Reddit has for the site instead. I'm sure that model gets more "engagement" (the skinner-box formula certainly makes a lot of money for other social media), but it also ruins what makes Reddit, Reddit.
Therefore for older users, it's not a matter of being "picky" that the app is "garbage". It's actually much worse than that. If the app was merely "garbage" there would be a holdout that the app could improve. Instead it's a fear that Reddit is changing the site dramatically to be more in line with modern social media. Those who like Reddit for being Reddit, and would rather Reddit stay Reddit than try to be Instagram/TikTok are obviously not happy with what they see as what Reddit is all about changing. There will be a similar outcry when old.reddit.com is inevitably sunsetted.
As a user who likes the old discussion board format of Reddit, I am obviously going to be unhappy when my personal favourite third party app (Sync in my case) dies. I don't need to doomscroll through skinner-box style feeds, getting a dopamine hit everytime a Twitter screenshot confirms my political biases, or strawmans opinions of those who believe differently than myself. Maybe I'll just go "touch grass" as the kids say these days.