How does this work if one or two players of a crew want to play but the others can't join? Does it at all? I'm interested in trying SoT when it hits PS5, but if it's gonna require a full crew to always be online at the same time I don't think that's gonna work out.
To expand on ManaByte's post, Sea of Thieves also uses Looking For Game (LFG) in game. You can make a post in LFG looking for other crew members for your ship or check the other posts who are looking for crew members and join their ship. While you are in game, people can jump in and out of your crew. Every time I check LFG, there are always 100-400 posts, so there is no problem finding people to play with.
There is also an Open Crew option where you can get randomly placed on a ship or a random person can get placed on your ship. This option can bring some unexpected random fun to the game, but it is also kinda a roll of the dice, so you may meet someone really cool or maybe even a troll.
I see posts all the time in LFG of inexperienced players looking for experienced players to show them the ropes. The community is pretty cool and tons of experienced players are more than happy to show new players around the game.