> by 2050 when, my bet, there still won't be any remotely viable QCs

I hate to be that guy, but I'm 52 now and I've been hearing about how Quantum Computing is going to revolutionise everything in the next two years, since I was in primary school and ZX81s were state-of-the-art.

At least a couple of manufacturers offered a practical and afforable(-ish) transputer-based system in the 80s that you could have actually gone out and bought.

Transputers have nothing to do with quantum computing. They're completely classical computers.

Yes, I know. I own some.

They were going to revolutionise absolutely everything to do with computing in just a couple of years, some 40 years ago.

I've been hearing the same thing about quantum computing for about as long.

I will take "Post Quantum Cryptography" seriously when I can buy a quantum microprocessor off the shelf.