I don’t even play D&D (and haven’t since before AD&D had a second edition) and I’m still baffled by what PbtA brings to the table.
PbtA is artschool D&D. Its a very different approach to the same concept that brings different aspects of the idea to the forefront. Its really good for groups that are good at acting and improvisation, but want a random element to help drive the more personal and less combat oriented stories they’re telling.
Personally it’s not my cup of tea, as I am absolutely into the fantasy and tactical combat side of D&D (well, Pathfinder), but it definitely has its place for groups that are just an excuse to hang out.
I understand the intent. (I’ve been playing “story games” since the 1980s…) For me the problem is that I just don’t understand the mechanisms. When I try to read PbtA-based games I get Nigel Tufnel in my head saying “these go to eleven” only instead he’s saying “these dice rolls go backward”.
And all the explanations people point me at presume I’m a D&D player (I’m not) who’s never seen a story game before (when, as I’ve said, I’ve been playing them since the '80s). I’m just at the point now where I presume I will never grok a PbtA game and pass them over automatically now.