There are plenty of ideas that Mojang has said that they don’t plan to add, such as the ones on this official Previously Considered Suggestions List. Even so, are there any such ideas (or ideas generally viewed as “modded” by the community) that you think would fit in vanilla and should be added regardless?
I’d personally love to see more furniture blocks like tables & seats and disagree with the idea that they “limit creativity”. Wooden tables, for example, could just have a scaffolding-like model that would fit right in with the game’s aesthetic (here’s an example I made), and they’d open up so many options for building. Alongside providing a simple option for tables, you could use them as stools, parts of pillars, or legs of other furniture. You could even use the top texture to decorate your floor.
I’d love to see most of these, the main exception being automatic villager trading. I don’t really want to see any buffs to villagers until we see a major overhaul that fixes some key problems such as really powerful trades and the incentive to cram villagers into tiny boxes. Add automatic trading, and villagers become a lot harder to improve, as people will be reliant on villagers working as they do for their farms to work.