Nowadays most use Bitcoin as an investment, not only as a store of value. But after some more halvings and after Bitcoin is mature and widely adopted, the value may become rather stable and using it as investment may not bring such high reward.
And Bitcoin primary meaning is to be used as a coin. The store of value is a "secondary effect" of all good/successful coins (back in the days when inflation was big I kept my savings in USD/EUR!).
That's why the development goes in the direction to make the use of Bitcoin-as-a-coin go faster and better.

So I expect Bitcoin get used in 2130 as a coin much more than today.
I don't know how much of the transactions will be off-chain and how much on-chain, but we clearly have to keep miners happy even then (the problems will start much earlier than 2130 actually).


As said by @Deathwing, the network will continue to work even then, just at a lower difficulty, if the miners leave. But if the difficulty drops too much, at some point the network could become vulnerable to 51% attack. So ... we have to find long term solutions to keep the miners happy.