Most games on this lists are, to my eyes, very similar, especially system-wise. There are differences of course and one could perfectly draw a line between all of them and have preferences. I do, too (among this trend of games, that's 5E I like the best). But if forced to choose three and ONLY three games for all eternity, I'd rather have very different games. PbtA is one, yes, and it's interesting that it is here noted as a system without any game attached. But I didn't even manage to choose a third, here, especially not a third system. I have an inkling Cortex could be it, but I don't know it enough to be sure.
All in all, from my perspective, these are almost all success/failure engines. A robust and battle-tested way to make ttrpg, sure, but far from the only one.
(This kind of list would be totally different if it were written on a french forum, BTW.)