No it’s still a lot. The 2 MB can be streamed. In HTTP 3 it can be streamed in parallel. But none of those requests can start before the connection integrity is verified, otherwise you leak the intent of the request to a MITM agent. So you have head of line blocking on that 12k. And on mobile networking that comes with a lot of packet loss.

If server certificates worked more like PGP you could probably avoid that, but that’s not how TLS works.