Apple's decision is not constrained by server logic or ballooning costs, it is entirely a client-based policy to not sign CUDA drivers.
Microsoft rewrote their Windows Phone native client to pass through Google's ads. Google still blocked it.
Was it normal behavior when Google blocked Amazon Fire devices from connecting to YouTube with a web browser during the Google/Amazon corporate spat?
To be fair, Google did back down almost immediately when the tech press picked up on it.
Not allowing a native client for your monopoly market share video service on Amazon devices while also blocking Amazon's web browser on those devices is making things a bit too obvious.
Clients are not offered at-will, they either work or they don't. Nvidia ships AArch64 UNIX drivers, Apple is the one that neglects their UNIX clients.
Google used YouTube as a weapon against both Windows Phone and devices running Amazon's Fire fork of Android.
You do own the client though. In the example upstream, the failure to support macOS clients can't be blamed on Nvidia because they already wrote AArch64 UNIX support.
This is as basic as antitrust law gets.
