This assumes that discrete payment networks still exist and are competitive. Meaning if bitcoin is the money/network that separates money from state, it's the global reserve, and everyone globally is using this same money, what incentive exists to attack and bring down the network? How is an attacker getting paid and how are they paying to attack the network? Mining requires a continuous expenditure of resources.

They'd have to overcome a collectivism problem whereby attacking the network is the financial equivalent of nuclear MADS (mutually assured destruction). This goes for individuals and states.

Where are nodes in all this? Would by this time silicon and hard drives shrunk enough, and software eased itself so everyone has a friction-free and full-service bank (node) in their phone or head? The bitcoin network's software, block weight, and blockchain size don't increase significantly.

Lastly, time and blocksize are issues because the difficulty adjustment doesn't allow an attacker to speed up blocks beyond 10 minute velocity over any period of significant time even with a sudden energy source and hashpower, and the blocksize/weight itself is quite small. They'd have to join a pool which their behavior disincentivizes membership from, or they'd have to be the pool themselves, which goes back to the original problem, how are they paying for and maintaining the attack? If it's a double-spend attack and not one to bring down the network, then it doesn't work, because of 10 minute block times and the small block sizes. The resources they'd expend would far outweigh their earnings in this regard especially after getting clipped by nodes for an ungodly loss.

Attacks like this make [some] sense currently for state level actors, but they don't when state level actors don't exist and we're all using the same money which powers the global economy.