I've never been to KitTea, despite living in the Bay Area, but I strongly endorse pre-COVID Paws & Whiskers in the Georgetown part of DC. Cozy, pleasant, and peaceful.

By comparison, Catnip in Norfolk, VA, was in a desolate little strip mall and full of very skittish black cats. I get that black cats are statistically the least desirable ones by pet owners, and I wouldn't object to having a black cat as a pet myself, but the ambiance there was kind of sad when I visited last year.