People like it because in so many ways it is way less expensive "glue" than zapier.

And given there are a lot of things that your platform does not do, it would be nice for example to have a website with a funnel (using any of the zillions of funnel platforms), have people buy a product and possibly an upsell (that may be on a different platform) and glue it all together with Pabbly.

I believe you have noticed that Pabbly seemed to be the second or third biggest request (second/third only to full white-label on tier 2 and possibly having an entire "group of coaches" practice (what you called a "marketplace of coaches")).

I'm a vote +10 for pabbly.
I'm a vote +5 for white label.
I'm a vote (don't need it yet) for more than 3 coaches. For now, it's just my wife and me (2 coaches).