The problem is they don't care about the mobile web and want you to use their native app where you're more likely to enable notifications and then increase engagement (everything is for ad views obviously)

Old reddit was designed for a larger monitor (laptop/desktop) and mimics the best design practices on that device over the past couple decades of bulletin board/forum software; makes sense why people like it so much

Design decisions aside, the site performance is horrible. I don't understand why serving content is so difficult. I get they have large scale, but they've also had that for quite a while and employ enough people to solve it if they actually cared enough