Not true at all. Like “admin” said, it’s cached in your browser so, even if Google slows down it won’t slow down the download time because it isn’t downloaded. For example:

Site A: Hosts from Google
Site B: Hosts from Google
Site C: Has their own version
Site D: Hosts from Google

When you get to site C you have to redownload it, but once you go to Site D it’s cached from A, so download time will be the same as site B. Even if when you get to B or D if Google slowed down you wouldn’t even notice it.

Also, C’mon, what’s the chance of Google shutting down? You honestly have a better chance of your own site being, hacked, shut off, lose power, fire (like Dotster), and other stuff.