Again, I agree that Unity's move is bad, they're just forcing people to their monetisation platform and to a per download system which will hurt a lot of studios.
The 3D/game engine for a studio is, in my opinion, the main tool that game studios will r to make their game. Without it, they won't be able to develop or it would cost them 100 times more. That's why I compared to the Uber driver's car, it's also his main tool for his job. Both cannot expect to have it free.
Well, unity's business model was always to make it free and then ask for a fee on revenue because it's easier for small studios. The alternative business model would be to sell a direct license of the 3D engine, which will likely cost in the 10s of thousands.
It's expensive building a 3D/game engine, they sell one to you.
I'm not saying their latest move is not a real dick move, but it's normal that they want to be paid for the product they sell. Uber drivers have paid for their cars, right?