There are not too many SFZ format mappings, because most of the creators of piano libraries here on Pianobook use Kontakt for library creation. It’s understandable, because it’s a de-facto standard and library creation is relatively convenient in Kontakt, since you have a graphical interface to drag and drop sample files available.
That being said: SFZ is a perfectly suitable format and has been used (mostly by non-commercial and small “boutique”) library creators for quite some time now. While you can easily create smaller SFZ libraries using a text editor (see @dhilowitz his video, he showcases an efficient workflow template for SFZ creation) , there are also graphical tools and auto-creation tools (the latter require proper file naming of the recorded and edited samples).
I’m really looking forward to more developers supporting the SFZ format hopefully, since it’s really useful to have if you don’t own Kontakt already.
I don’t really get your point.