For me, at stash is a requirement for creativity. I also don’t consider thins that are basic to my mediums to be stash or at least not troublesome stash. Neutral threads, a bazillion types of adhesives, half a bazillion pairs of scissors, and the like. I have mostly stopped buying more specific stuff (novelty prints, etc.) just to stash it which I feel great about. But I still have some of that stuff and still have the remnants and scraps-of-a-decent size from completed projects. I mean, that’s how I was able to make a bunting from underpants scraps, right? 
It was fun to make and I love how it turned out, but it also did not really diminish the overall volume of stuff in my possession.
Two things stand in my way of really purging:
- I can’t just throw these things away and there aren’t good donation, or even selling, options for most of my kinds of stash.
- I don’t really like to give gifts that aren’t specific to the recipient. So like, while I may have a print that I know someone would like, they wouldn’t necessarily want anything I could make from it. Like they have all the potholders and coasters and throw pillow and whatever already or are not the fabric bin/bowl cozy/cloth napkin type. Also, only one of the friends that I exchange gifts with is not in a down-sizing/purging/minimizing mode.