You're giving Reddit way too much credit. It's not that challenging for something as simple as a forum app. The real "challenge" is the very, very large difference between what's optimal for users, who want content; and what's optimal for the company, who wants all your data and ad clicks and couldn't give the tiniest rat's ass about what the users want.

The official app is built on top of Alien Blue, which used to be considered the ideal user experience. They could have done nothing but OS support updates and it would still be perfectly fine. The entire current unusable clusterfuck is COMPLETELY INTENTIONAL FROM TOP TO BOTTOM.