Maybe Forgotten Realms has enough high-level characters for that sort of thing, but certainly in my world, a 14th-level wizard (or any class) wouldn't be selling services - they'd either be an adventurer or a ruler in their own right if they wanted to amass wealth/power.
And there are probably cities that do have magically-lit streets, but they're far from where the adventurers are likely to be, since there isn't much for adventurers to do in the 'heavily-civilized' parts of the world with high-level residents who are interested in preserving the status quo.