Well, we are not the hot bed of quilting we once were. Pacific Fabrics is shutting down to two stores, but SoDo and Bremerton will remain. edited comment: SoDo store used to be part of my cheap tours of Seattle, but they reduced their flat folds and started selling for the same price as in the regular stores. At least Costco still has cheap hot dogs!
From rumors, we almost lost Gossypium in Issaquah but it seems to still be there.
https://www.gossypiumquilt.com/
I recently went down to Running Stitches in Kent for the first time. It was my first time in a quilt shop in at least a year and I was confronted with many things I wanted!
https://www.runningstitchfabrics.com/
There is a place opening again in Renton soon (Pieces has been gone for many years), but it doesn't sound exactly like a fabric store.
https://www.wyldwoodcreative.com/
Haven't been down that way in a couple of years but Carriage Country in Des Moines is still open.
https://www.carriagecountryquilts.com/
Probably not what you have in mind at all, but Hobby Lobby has come to the area and there is one very close to Gossypium, they are maybe 8 blocks apart.
Final Thought -- we have a non-quilting fabric store in Renton that is awesome for fancy stuff, evening wear, costuming, etc. They used to be up here in the Highlands but (long story) have moved to down by the Airport. Well worth the trip if you need trims or just want to play with fancy stuff. Much of it is imported directly from other parts of the world -- do a sniff test, it is my personal issue that moth ball smell never dissipates enough for me.
https://www.facebook.com/fabrisforless/