Most of the people I know that play video games play a wide range, and I highly doubt that steam could have been a fraction as successful as it is if “95% of the people play one game exclusively”.
Although this is a separate issue to the greater point that most people play one game. My bit of anecdata is that me and all of my friends might try out some flavor of the month game or something that caught our eye on sale, but those tend to be one-and-done playthroughs. However, each of us has a game that they play regularly that has an order of magnitude more hours on it than everything else.
I hear your doubts. To be clear: I never said 95% of the people play one game exclusively. I said 95% play two or fewer games. What I should have said was probably 90% of the people play two or fewer games in a year which I think is more accurate.
How can Steam make so much money? Well playing two games doesn't mean you own two games. Many many games are "purchased" on Steam and never played at all. The two games do change over time, though not quickly. Also, there are a lot of people out there with Steam accounts!
Besides my kids as evidence, I can't really link to research I look at. I am a 25 year game industry veteran who runs the interactive division of a small entertainment company. So I guess I can site myself as an expert :) Which you can reject.
If you like Fortnite you play more Fortnite. You might try another game like Fortnite, but only one or two games and you are probably going to settle on one. Same if you are a fan of CoD, GTA, Madden, etc. In general you are not trying a new game every month the way you might see a new movie or read a new book.
There are some gamers on Steam who try lots and lots of different games all the time. Everything well reviewed, things on sale.. etc. My kids are like that. But gamers like that are rare. 95% of the people on Steam play two games or one exclusively.
Therefore I don't see a rise of services that are like "Netflix" for gamers. Digital DRM channels like Steam, Origin, Epic, etc. will continue to thrive because they let you buy the thing you really want. I question the long term major success of things like Apple Arcade. People who will pay for games want to pay for the game they want most. They don't mind getting other games, but having a library to sample is of dubious value. I can see the point if you are a parent and you are buying for your kids so it will continue.
Otherwise I think this article is great. Yay gaming industry!