I think it depends on what you mean when you say "synthetic meat".

I use quorn mince when I'm making spaghetti bolognese and lasagne. If you add marmite to the "mince" when you're doing the initial cook the final dish is indistinguishable from real meat tbh.

I agree that other meat replacements aren't the same and probably won't be for a while, although Aldi have recently started selling something that resembles a steak which I want to try.