Some browsers and some end user devices get upgraded quickly, so making it easy to make it optionally-PQ on any site, and then as that rollout extends, some specialty sites can make it mandatory, and then browser/device UX can do soft warnings to users (or other activity like downranking), and then at some point something like STS Strict can be exposed, and then largely become a default (and maybe just remove the non-PQ algorithms entirely from many sites).
I definitely was on team "the risks of a rushed upgrade might outweigh the risks of actual quantum breaks" until pretty recently -- rushing to upgrade has lots of problems always and is a great way to introduce new bugs, but based on the latest information, the balance seems to have shifted to doing an upgrade quickly.
Updating websites is going to be so much easier than dealing with other systems (bitcoin probably the worst; data at rest storage systems; hardware).
Which one do you think is PQ-secure?
This is the result of Cloudflare's test "Check if a host supports post-quantum TLS key exchange" offered on https://radar.cloudflare.com/post-quantum.
Hoping there is already a migration plan. Fortunately many modern tools make it easy to switch to PQ, maybe someone knows which stack HN is running and if it would be possible.