*The* defining feature of single-payer healthcare is that it limits a nation's healthcare system to the funds that can be raised through taxes. To complain that a single-payer system fails because it is underfunded is to acknowledge the central reason it is a bad idea. https://twitter.com/awgaffney/status/1245012412643921922

This thread, from a British perspective, gets it: https://twitter.com/JeremyCliffe/status/1245121448307499009