Is the Sea of Thieves playerbase really small? I thought people said it sold really well or had huge Twitch numbers or whatever it was, so I would not have thought that alternate styles of servers would be that detrimental to the playerbase. I've suggested a solo-only server option a few times before and could see it as a way to bring more people into the fray and may lead to them graduating to the free for all servers if they gather a crew. The lack of ways to gather a crew in the game without random matchmaking is also an issue, as I'd consider joining a crew if I could ensure that I'd be matched with people that are similarly minded as me and don't want to be jerks in the game. It doesn't seem like there's much of a community in the game since it's all about free for all where everybody has to fend for themselves. Can you let people you meet in the server join your crew or does it have to be set-up before playing the game?
I've said here before that I'd love something as simple as a solo-only server for people to be on even terms with others on the same server where they could just explore and have fun on their own terms for the most part and have a shot at defending themselves against attackers compared to now where solo players are going to eventually just get bullied out of the game completely every single time unless I plan on getting on at times where nobody will be on. It's cool, legit, and valid if you want that experience, but I'd bet there are a lot of people that would like something that's a bit less hostile to people that just want to chill out, explore, and have some fun. I'm coming from a point of view where this could be an amazing follow-up to Wind Waker and it can't come close to that game due to the hostile PvP being the only way to play it.
I don't know anything about voice chat with the game because I turned it off early on when my social anxiety caused me to quit the game abruptly at launch when something kept following me around the markets while mentioning my username. I don't recall there being any other way of communicating with people and haven't seen any sort of quick chat option either. I'd have figured that having plain sails would be a good way to signal to other players that I'm not a threat to anybody and that I'd like to be left alone. I don't think I've been able to finish more than a few quests due to jerks harassing me in the game and my first attempt to complete one of the story missions went horribly with no real way for me to deal with it as a solo player. I'm just supposed to take it until they get bored or scuttle the ship and try to figure out whether I want to bother with restarting the quest or moving onto some other game. If that's the experience Rare wants, then they've done a great job.
I've played a decent amount of Fallout 76 and with 24 players on a server, I haven't seen many jerks around whose sole existence is to ruin other people's fun. I did have a guy walk into my camp and try to shoot me when I was under level 5 when that's not an option, but that was it for the most part. People tend to come together for events rather than be jerks to each other.
