Stressing that advanced hypersonics is venturing past nuclear MAD but building towards conventional MAD made feasible by proliferation of advanced rocketry as dual-use components become commoditized and US/west lose monopoly on space infra used for targetting/guidance. It's a new kind of mutual vunerability where strategic infra that underpins modern society i.e. semi fabs, server farms, energy nodes, captial ships docked for maintenance etc can be targetted by more and more players.
In terms of practicality, we were "stuck" with nuclear MAD because meter level surgical intercontinental strike capbility has so far been pipe dream. With nuclear MAD, we had stability-instability paradox, increase chance of low level conflicts against non nuclear states while nuclear states operated with relative impunity. Conventional MAD = even 3rd rate countries can potentially import a bunch of global strike ICBM platforms to threaten pain points of any would be attacker. Most countries can't sustain modern airforce let alone forward project carrier groups, but many countries can build some concrete tunnels to hide sufficient amount ICBM TELs to increase deterrence. It's not nuclear tier deterrance, but ability threaten some critical infra is better than current posture where most countries can't inflict pain more than a few hundred km outside their borders.
I don't know how things will change but my position is balance will have to shift once advanced rocketry proliferates because that's boat that everyone will want to rock simply because dual purpose conventional rocketry won't be subject to arms control. It's going to be about how states with advanced rocketry programs can control proliferation, i.e. US wants to seed Asia with IRBMs that can threaten PRC, and PRC starts exporting hypersonics to South America or other countries that can threaten US global assets.