Nothing in a background requires anything to happen. If you are looking at it like that no wonder you dislike them. Luckily, that's not the case at all.
But if your plan involve the characters traveling to an island, you can get some instant buy-in if it's Bob's Island.
Just like if you had a plot that needed a horde of low CR monsters, and one charater's village was wiped out by gnolls - picking gnolls instead of hobgoblins or whatever is no skin off your nose, and can get the player invested. If gnolls never comes up there's no harm, no requirement that you must use them. Just a way that you can get the players more involved with a fantastic return for the work involved.
Need to come up with a trustworthy questgiver, maybe the mentor of one of the characters? It is the less work for you since you already have a name and some details, and establishes it immediately and gives the character a reason to want to do the mission.
A background literally doesn't detract anything or require anything, it's nothing but bonus for the DM if they have a place to fit some of it in.
And so long as the DM treats it as such, great! Those players that want that sort of buy-in get an opportunity and those that don't lose nothing.
Some DMs don't treat it as such.
I've had some DMs that claimed falsely that any player that didn't provide a background just wanted to be psychotic murdering hobos and would attempt to force players into providing them via in-game punishment (unluckiest PC), metagame punishment (reduced xp), assigning a background without consultation (because that makes everything better!), or dropping the non-conforming player.
Other DMs use the opportunity to inject extra advantages and privileges for PCs that catch their fancy. So providing a background is akin to buying a lottery ticket. Sometimes it pays off handsomely.
Still other DMs feel the need to 'fiddle' and implant secrets and drama inside of any background provided to the point the players become exhausted and unwilling to trust anyone from their past. "Hey Bob! I'll bet your doting mom is actually the centuries-old lich bent of erasing all life this time! Nah! My bet is she'll turn out to be the daughter of a devil/demon hybrid that's hiding on the Prime until she can gather the forces to usurp both her parents and will need to use me as a sacrifice for the final acquisition!"