I don't understand how such a large company can have such abysmal customer support
It doesn't matter how big the company, if the customers don't push for a thing, they won't provide it.
Google's primary income is advertising. Their users are not their customers, at least not most of them. They don't see a significant loss of revenue when users are just fucked over by their lack of support, so why bother?
Frankly, there needed to be a regulation here of some kind to force companies like Google that control user accounts like this to provide a minimum level of support when their accounts get locked. People's lives are tied to those accounts, being locked out of them for days can have serious negative effects.