I've been using 3rd party apps for over 15 years -- I used Alien Blue on iOS when I had an iPhone and I bought Relay for Reddit on Android over 10 years ago. I use old.reddit.com and always have (back when it was just reddit.com).
How do I find and read that content that I like? It's a very different (and, for me, worse) experience in their official reddit app and on the non-old Reddit.com.
If I'm going to adjust to a different and worse way of browsing content, I might as well just go to a different site entirely. It's similar to how Microsoft keeps adding user-hostile features and degrading the UI on Windows every year. Most users will stay (I do) but a few more will move to Linux or Mac OS. I fully understand where you are coming from -- for you nothing has been lost. For me, it's a significant change for the worse.