Or https://taginfo.openstreetmap.org/tags/shop=plumbing_supplies#overview (less popular but harder to confuse with plumber office, both values seems undocumented)

BTW, do you have an image of such shop interior? Or uploaded already by someone else to Wikimedia Commons?

I could try to document such value, like I did with https://community.openstreetmap.org/t/shop-safety-equipment-is-there-a-better-tag-for-that/102125