I hate to be pedantic (this is a lie), but I’m pretty sure Worlds Without Number is actually the fantasy version of Stars Without Number, since Stars came out first. This doesn’t change your point (also I agree with you) and I’m really not sure that this information is helpful in any way, but here we are.
Having played Monster of the Week, I think I agree with you about PbtA systems. They’re fun, but I tend to get a little bored with them after a few sessions, especially since I like to make characters who don’t really fit into any of the playbooks. The best fit of a playbook at character creation rarely has more than a few plays I would want to spend experience points on.
I will say, though, that I like the experience system in PbtA games. It does a good job of helping players feel like they accomplished something each session.