It doesn’t matter if old.reddit.com is still there. Only a tiny percentage of people know about it and use it. Everyone else is posting from the new website or app, and largely from phones, which absolutely has had an impact on the culture there.
For example, subreddits used to have FAQs and wikis in the sidebar. The redesign hid all that, so on many subs people are asking the same questions over and over again. Mods who lock such posts and refer posters to a FAQ, often get lambasted by the community, who can’t see any FAQ. This may have been an intentional part of the redesign, since repetitive posting registers as greater “engagement” for Reddit’s metrics.
I dont think Reddit would want to make their own internal metrics worse, they arent getting paid for that. They needed to go mainstream though, and the best working tactic out there was (still kinda is) simplification and infinite scroll. Reddit did both.
They're intentionally killing it slowly through malicious neglect. It's already unable to deal with some things in user profiles and the image galleries which force you into the new awful.
