Once you deploy it it will be there, forever running on a decentralized immutable computation machine which is made up of nodes and miners all over the world being incentivized a certain way.
That kind of certainty has a beauty to it.
There’s little to indicate it will be there forever. Today’s computers are tomorrow’s stone tablets.
For sure, I guess you can say it will there for as long as at least one person in the world (or in space, not sure on your timeline) keeps running the node software. It doesn't rely on any companies or currently existing groups of people.
The point is that you don't have to pay for its continued existence, in direct contrast to putting a compute instance on AWS or any other cloud provider.