There are so many voice+video apps that are very good. Support one that already exists over the NiH temptation.

"Never decided in court" is very different from being allowed. GPL experts (such as the ones who wrote the GPL) are pretty much all in agreement that at least most (and very probably all) Linux kernel modules are affected by the GPL. There is litigation ongoing related to these issues (such as the VMware case).

Nvidia and AMD are famous examples of violations that no one enforces against.