That's a long road. Plus, short of cutting off support for legacy versions you would not mitigate downgrade attacks. On the flip side, if we're ever going to go

That's a long road. Plus, short of cutting off support for legacy versions you would not mitigate downgrade attacks. On the flip side, if we're ever going to go down that road it needs to start somewhere. A middle ground might be a modern stripped down TLS stack and something similar to HSTS to externally flag that a given site does not accept downgrades.