The idea is that eventually ECH will roll out, and then Google and Cloudflare can start offering this from the same IPs that they do the rest of their services, which there will be way too much collateral damage for the censors to block.
State-level censors will at first ask nicely to block specific entries for their ip ranges; either the provider cooperates (then DoH won't help at all) or not.
If not, they won't have problem blocking entirety of Google or Cloudflare, collateral damage be damned. It would be as much Google's or Cloudflare's problem as it would be user's, so they won't do it. They don't allow domain fronting either.
