When Does The Campaign End?

I have successfully managed to play a campaign with fewer than two sessions a year.

That campaign is technically still out there, but I think I didn't start it properly and it is thus painted into a corner.  It's defacto dead even if it's not dejure dead.

Marv and FuzzyGeff are at a cliffhanger in Twilight: 2000 and that campaign will run until one of us gets sick of it.  I will badger them to keep playing until that someone is me.

But when is a campaign over?

I don't tend to make settings that have an end point.  You don't reach a conclusion to the story there.

There are campaigns that DO have an ending point.  If the players reach that point, the campaign is over and they win!  Or they fail and give up or die.

I've had several campaigns just peter out and stop.  Most times when I run out of ideas for the world that I'd created.

I've had a few where the players stopped showing up.  Hard to keep going when there's no way for a player's character to be absent from the world.

I've even had a couple where the players flat said they didn't want to continue that setting any more.  This happens most often in Traveller where the party is the crew of a merchant ship.  Economics & Accounting is not near as exciting as it sounds.