I’m strongly suggest to use this tag and add it in the preset schema. If year ago was not common to have shops selling accessories only (covers, earphones, chargers ecc), now we have smartphone case chain stores and a lot of kiosks in the malls.
The lack of use of this tag it’s because those stores are tagged as shop=mobile_phone.
It’s a good tag, no icon yet on Carto S, just a dot, but at least the name appears. Added/changed a few shops and a permanent stand in a corridor front of a busy supermarket checkout area.
At any rate, mapped a few since using this tag, quite a number here in town.
The stand has been there since at least 5-6 years.
It seems good to me also, as previous replies have said I am familiar with a lot of shops that fall into this category and don’t have any good other tag.
So long as it’s clear that shops selling both mobile phones and accessories are not covered by this tag (and I think it is), no problems come to mind.