Want to expand replies? Entire thread reloads and I have to scroll down again.
Want to go to a "controversial" sub that doesn't do front page bootlicking for billionaires and/or "influencer" sociopaths? Too bad, you need to log in. I have nothing left to log in with because fuck that.
Want to go to a less controversial but still cringe sub? Here's an introduction blurb and the rules but you need to log in. Like and subscribe. Ring the bell to keep ahead of future notifications. Eat Feastables. Eat the bug vomit chocolatey bar. 
half that and half it being a super waste of time and money to make their web UI work well on small screens on mobile browsers which already don't work very well in general (and the web doesn't in general either).