> I do fully understand people who can't get their heads around threads and prefer async.

Those are independent of each other. You can have async with and without threads. You can have threads with and without async.

Yeah, it always mystifies me when people talking about async vs threads when they are completely orthogonal concepts. It doesn't give me the feeling they understand what they are talking about.

It's because JavaScript was the thing that popularized async/await for many developers, and they aren't aware that it originated in a language (C#) and runtime (.NET) that are fully multithreaded.