I personally very much prefer buildroot over yocto, which feels bloated (my opinion only). However buildroot has some shortcomings that are important to me (for example it lacks a package system, which makes it difficult to do partial updates). Ptxdist adds this and also some other useful stuff, such as a mechanisms for “layers” (similar to Yocto).

I guess for me it just hits the sweet spot between simplicity and flexibility.

My company has been using it professionally since 2014, and we are very happy with the results.