There is no way that this can work "as advertised", it cannot hold all the files that anyone needs to store on their PC.
I have ~1TB of files on by PC at the moment, sure this may be more than average, but surely not uncommon (otherwise why can you buy drive > 1TB each).
My ASDL link is pretty nippy managing an effective 6-7Mbps downstream, but only ~400kbps upstream.
So, if I install GDrive today, uploading all my files will fill the upstream pipe for quite a while:
1TB = ~8,000,000,000,000 bits (they are storage TB, not TiB).
If I transfer 409,600 bits per second that will be 19,531,250 seconds, or 325,521 minutes, or 5425 hours, which is 226 days.
But now if can manage to devote my entire Internet connection to setting up GDrive for seven and a half months, what about when I want a file?
There is no way that the Internet is going to cope with the amount of bandwidth that transferring everyones files backwards and forwards every time they are used. If bandwidth were that plentiful ISPs would not be capping everyone!