- They change you back to the new design every few days.

- They constantly tell you to use the app (thankfully you can disable this at least).

- The old reddit design has a sidebar with helpful content, but this is not automatically present in the redesign. If you're a mod you have to manually copy that content over to the redesign and keep both updated separately. A lot of mods don't seem to know this so some communities just don't have their community information in the redesign.

- The new redesign on mobile web is so bad that those that don't know about how to get the old design will probably use the app to get something that works.

I'm glad old.reddit still exists, but I think if they just scrapped the entire new site it would be a better product. Probably worse for 'engagement' though because without infinite scroll, gifs loading everywhere, and other addictive hacks, people would just read what they wanted to and leave. The horror.

(Also r/hnblogs traffic has most people using the old design, but there's an obvious selection bias in that community.)