Of course, Alfred and Everything are more mature products. My motivation was: (1) Build something on my own (2) Build a dedicated full-text search only product

I was trying to scratch my own itch really.

To this list I'll add Thomas Tempelmann's excellent Find Any File for Mac (NMNA):

https://findanyfile.app

Still, I like Buzee's UX and 10/10 agree it would be a major step up for Windows users.

Alfred is amazing, but it's Mac only.