Certainly give it a try, who knows. Maybe I haven't found the right server and group of people, but maybe you will Discord is free to use, any how, so no harm in giving it at least a chance.

It'll definitely always have the chatroom vibe- being a chatroom and all- but how structured a server is will vary between them. I'm not a public server type of person, but I have personal servers with individual friends that are decked out with tidy categories, so I do know it's possible for them to be more structured.

Most servers are invite/link only, so it's totally normal to not be able to query the majority of them. You usually need to start from whatever site or blog it's associated with, where the invite link will be. On ModTheSims for example, if you click the Community tab there is a Discord option that takes you to Tashiketh's invite.
I've never joined, even though I've made over 440 posts at MTS in exactly a year to this day, because if I were to assign myself sim traits Neurotic and Coward would certainly be in there

Knowing it works like that might help you scour some more.
It's also free to make your own, if you just want to make one that has all the sections and topics you desire. You could put the invite link in your signature at other forums, like here and the EA one, until some more users join. Sometimes when you want your cake and to eat it too, you have to bake it yourself. That has been the driving force in pretty much everything I've ever made.

I've been looking into hosting options myself, but that's a project that will be a long time coming.

I totally agree with the general tone of the conversation. I wander around here, boolprop, and mts forums, plus I'm active on tumblr, but there's a conversation that should be happening that is hard to find.

There are some forum threads that have the kind of casual conversation about the game that can be fun. "What did you discover today?" on MTS is reasonable active and fun: https://modthesims.info/showthread.php?t=349023

This reminds met to hang out on some of these threads more.

Tumblr is active, and I don't really know why it doesn't foster a more conversational atmosphere. I've had to work for the conversations that I have there. Considering how active the community is, sometimes it can feel quite isolating.

Tumblr's design innately makes real discussion difficult. The notes structure is just a list, and if there is any back and forth it's hard to see. Nothing beats an old fashioned news group or forum for conversation.