My take on this:
If (hypothetically) everyone just hodled and no tx would be sent across the network, most miners would just switch to a different cryptocurrency.
Let’s say hypothetically every single BTC miner switches to some other cryptocurrency.
No miners = no transaction confirmations = the system ‘‘freezes’’. You can still access the Blockchain and look into it (look at past transactions), but no new blocks are being created. The whole system is basically frozen until a miner starts mining BTC again.
Now, if everyone knew the coin wasn’t being used, no one would want to buy it anymore, because it would be useless, so demand would go down. With lower demand comes lower price (because of the supply/demand correlation). With a lower price, BTC hodlers would start dishing out sell orders to get their profits out asap, but as we said there are no miners in the network, so no tx are being confirmed.
So if hypothetically no miner comes back to save the network, people would just have to face the fact that their money is gone and they’d have to abandon the network.
So the system would still be there, it’s just that no one would be using it.
I hope this helps a bit