Probably because a commercial developer is not going to want to link a LGPL library with their program. [0]

https://github.com/systemd/systemd/blob/main/src/libudev/lib...

Because this is the fallback when you compile without udev support

I can guess that, but I was wondering why ... Is there a distro without udev? The steam/whatever sandbox does not support udev?

It's not the system that is not supporting udev, it's the choice of the game developers how they compiled SDL .. without dependencies, and so without udev.

That's standard for game devs in the Linux world. The less dependencies you have to rely on the distribution for, the better - Windows stuff is either already present or shared OS-wide with binary backwards compatibility (=DirectX), so you can get away with shipping stuff that has a chance to run even 25 years in the future without major modification.