We need unions for many reasons, but an employer offering optional housing onsite really isn't one of them. It's not like it's required to rent from Google to work there.
These days, that's cheaper than a lot of places rent for and you get free maid service. Fucking Google might have accidentally stumbled upon something helpful. And $99 a night is not profitable for the sort of hotel their employees would actually want to stay in, so they still lose!
This is only a temporary promotion. Tge price is not going to stay at $99/night, and it's not an alternative to rent, but in addition to it. This is not permanent housing, they're fucking hotel rooms.