Plenty of writers have written about places they've never been
As an addition to the methods they used, this is great - you can SEE how the buildings attach to one another, just how difficult it would be to duck down that alley....
It's an addition, not a replacement
Sure, most of us write about places we've never been, but unless you go one heck of a lot futher in your research than Google, you'll write poorly about that place.
Seeing is good, knowing how buildings are attached is good, but it's still nothing more than a photo, and a bare bones start to your research. What's on the other side of that alley? Where does that door halfway down the alley lead?
Seeing alone is dangerous. Thousands of manuscripts arrive in slush piles each year where the writer HAS been to a location, walked trhough it once, probably snapped a bunch of photos, and then thought he could write about it convincingly. He can't from this alone.
I'm not saying the Google method is in any way bad, but it's still just photos, and highly deceptive. It's nothing at all like being there, and being there is nothing at all like actually spending some time there at different times of the day, different days of the week, etc.
If you can't be there, use photos AND various kinds of maps, yes, but you really need to talk extensively with pople who do live there. You have to
know the place you're writing about, or anyone who has lived there, or even spent much time there, is going know quickly that you never have been there.
The internet leads many to think you can actually visit a place online, and you just can't do it.