The more shocking (yet totally obvious in retrospect to me) thing is that, of the 5, only Amazon doesn't have any way for me to escape their collective sphere of (direct) influence at all. I can switch to Linux on commodity hardware, use an alternative browser, use free alternatives to any MS product or service, and switch search engines, but there's no way to replace the Amazon shopping experience. I'm also not sure what I'd do about maps or phone platforms.
Even if I replaced them all directly, I'd still have to deal with compatibility issues for browsers and software, and it's hard to beat AWS. Switching to a more traditional hosting setup is s nightmare by comparison.
Can anyone here easily escape all of the "gang of 5"?