https://www.pcgamer.com/games/mmo/mmos-dont-give-people-the-tools-to-build-community-anymore-says-everquest-2-creative-director/
"The couple other MMOs that I play I'm almost like a solo player 100%, I don't group with anyone."
Indeed that is the case, the way you build community is to make it not fucking optional.
Dungeon finder that gets you into a group and conveniently into that dungeon? Nope, do it yourself by chatting with people and finding a guild, clan, whatever that suits your needs.
Map markers that show you outright where to go and what to do? Nope, figure it out yourself or ask someone who may know.
Allowing crafting to have a good place In the sandbox by making it valuable and requiring several different professions to get to the good stuff? Yes please.
Don't Introduce NPC's that allow you to circumvent the need for other players.
Make it inconvenient to transfer items between your characters on the same account or multiple accounts of the same person. The original mail delay in WoW between characters did exactly that.
Ensure that direct trade is always better than using a big market place.
And that is just off the top of my head. Building good community happens when it's needed and there are consequences for being an ass. Back then you couldn't just find a new group of people on the server you were on. Of you were an ass to everyone you would end up on ignore lists and make your own life so much harder. At the end of the day community only works if there is a need for community.