We use a game format known as "Round Robin" for our campaigns.
Simply put, one of us comes up with the meta-plot, the overarching campaign goal. It's specifically something indefinite or hazy, such as "Collect the missing volumes of Aristides work taken from the Great Library of Alexandria." Since nobody knows how many works there are, you can drag that theme out as long as you like.
Next, everyone makes up a character. They also make up their own home town/kingdom/land. That is, they tell everyone the name of it and pick a place on the map for it, as well as sharing whatever bits of history or knowledge that might be known to outsiders.
(By the way, when i say "everybody", that's exactly what I mean. No one is purely the DM in this style, so if there are six people at the table then there are six PCs made ready.)
Now somebody gets the ball rolling. That is, they have an adventure that brings the great seekers together. They set that game in the home city/kingdom of their own PC (who is an NPC or completely absent for this part).
Once the party has finished this part of the grand quest, they pick up a clue to the next stage, which happens to lead them to the land of one of the other players' characters. And so off you all go, including the old DM's PC.
The DM duties are passed to the next person so the old DM can have a turn as a player, and the new DM's character is now the NPC. They need to visit family, deal with some personal issue, or maybe they just can't go home right now and will wait for you guys at the border.
Each adventure leads to the next this way, all within the common game world, but compartmentalized by kingdom. I can't mess with your kingdom without your permission, and you can't mess with mine either.
The DM's character is earning loot and EXP equal to whatever they handed out, so they don't fall behind, but that's all behind the scenes.
Now how will it all be resolved? who holds the key to the great quest, or whatever mystery you're working on? Nobody knows. That will evolve as each DM adds their own plot twists, introducing clues or plot hooks, then handing the tale off to the next DM.
Now in our group we have a lady who doesn't like to DM, and that's fine. It's not for everybody, so coincidentally our quest never seems to take us to her homeland. It's all voluntary.
It also seems to work really well. No DM burnout, and some really creative story lines.
Of course, it takes some players willing to play along, and not everyone is up for that. And yes, we've had to disinvite a troublesome player one time. (It turned out he didn't want to play D&D so he set out to ruin the campaign. He had a Death Star, Droids and laser rifles in his land. Two guesses what he wanted to play, and the first one doesn't count.)
It's a different sort of way to start and run a game, but it's worked for us for the last decade or so, and we've run four campaigns in that time, three of them from level 1 to Epic. (The 4th Ed game petered out after 10 levels due to lack of interest.)