My immediate concern with tags is descending into what Twitter has become: hashtags have been meaningless for a long while since there’s too much wrongly tagged stuff, different communities often use the same tag for different things, or there are ten tags all for the same thing. All of which means we’d need some form of moderator role that handles tags, and while I think it’s doable, it might take some trial and error to figure out how exactly we divide tags between moderators, how tags are proposed/created, and how tags are grouped/combined (e.g. food, foods).
Lemmy technically doesn’t hide your likes - the interface might not show you, but all your likes are public in the Fediverse. Kbin, when I used it, would show which users upvoted/downvoted a post. That’s important because it means researchers and OSI people can still do fact finding - Twitter doesn’t like the idea of having to be open even if it’s a requirement (albeit to researchers specifically) in the EU now.