What an artist wants

Artists have different criteria from commercial illustrators. The latter control most of the money, so they are the ones catered to by the proprietary vendors.

To an artist, a sharp tool that might cut you is much better than one that won't cut. If a library of effects / textures / filters is interesting to an artist at all, it is as examples of tools they might cobble up themselves, if they could. Don't be surprised to see them make only one, haphazardly, and then spend weeks or years exploring how it may be abused, moving on to another only when they feel its potential is exhausted. Expect them to be interested only in tools that are hard to describe, with results hard to recognize, and whose potential seems inexhaustible.