A few of those aren’t on Washington Street, and 600 Washington is residential isn’t it? Beyond that the there’s the Kensington, Ritz Carlton (residences and hotel in separate towers), Godfrey Hotel, Millennium Place, Millennium Tower (biggest building downtown), Emerson Dorms, Suffolk Dorms.
If you insist on including the Arch Street buildings, then you’d need to consider 45 Province and AVA Theater District.
No way is there “way way way” more office along Washington than retail, restaurant, and hotel/residential.
Note my criteria--millions of square feet. There are millions and millions more square feet of office on Washington St., from City Hall to Boylston, than either residential, retail, restaurant. More than all the others combined, in terms of those uses' aggregate square footage, I bet. Simple fact. Easy to prove.
(By stopping at Boylston, I'm excluding AVA, Kensington, 660 Washington)
(If you want me to prove it to you, I will do some cursory research and send it to you privately so as not to belabor it on this thread. But it's not even close, in terms of the dominance of office over the categories, when it comes to square feet.)
600 Washington St. is office, not residential. And most of those I quoted with non-Washington Street addresses in fact front on Washington (60 Temple Pl, 1 Devonshire, Filene's building, 10 School), etc.
Anyway, the larger point is, "mixed-use" is one of those trite, way overused cliches that people toss around--but it really does apply to Washington St.! It contains *mass quantities* of everything--residential, retail, office, hotel, restaurant, theater--other than lab.
So, propose whatever the heck you want along Washington St., in terms of use characteristic! Regardless of the use you propose, you'll be in a giant, diverse market for it.
*in the spirit of Beldar the Conehead