Minority, in fact. You're wildly exaggerating, as is the article.
Half of Facebook's monthly actives barely use the core social network service. That leaves a billion people or so. There are 7.x billion people on the planet. Your majority premise just collapsed.
Google has about 1/3 of global adults as users, with varying frequency. Gmail as an example, has a small share of global email. Again, minority.
Amazon is still a trivial ecommerce presence outside of the US, as a whole and in relation to the number of adults shopping on their service versus the total number of people on earth.
And Apple? Their reach, like the others, is dramatically less than the "majority of humans." Apple reaches a billion people.
Facebook: nothing else has the network effect.
Google Drive: online documents are really convenient
Google Voice: what else has seamless integration with either android or ios.
Amazon: Buying household items like toilet paper, dishwasher detergent, etc, saves me a ton of time.
Google Drive: Dropbox, Box, OneDrive....
Google Voice: Depends what you're using it to do. Amazon & Microsoft have apps you can use that do similar tasks. Whichever you use does require access to a lot of personal data to be useful though, no matter what company you pick.
Amazon: Target, Walmart, Jet, etc... Lots of competition here. Amazon's online experience is typically better but their is plenty of competition & they often have cheaper prices. FYI in case any Target person reads this. Your site is terrible & full of bugs.
Voice is probably the hardest one to replace all 4 of them on.
For Facebook's network effects, I mentioned Twitter which is not one of the four. I did mention that my main use I've replaced with Google Photos. I did that because it's free & great. If I hated Google, I could use several paid services that offer similar benefits. Snapchat is becoming more popular with the older people I know. Instagram was great before getting bought out by Facebook so we can't count them now.
I think maybe one point that needs to be made, is if you want a "free service" you must be willing to let your data be sold. That is the big problem that many people have with a lot of the above free services.
You can even install an open-source replacement for the core Play Services Framework that many non-Google apps seem to require.
Take phone as example: You almost only have two main options for a smart phone OS here: iOS (+ Apple) and Android (+ Google).