If there were some hidden feature that was not enabled on an Intel 100Gbps NIC, which could be enabled in an open source driver, I'm 100% in favor of doing that. Thankfully there isn't (all praise to our benevolent corporate overlords), but I can certainly see a scenario with another vendor where there might be.

I hope that if Intel were to ever go down the route of big ugly closed source binary blob to make a 100Gbps NIC function properly, that people would go buy hardware from another vendor. With some basic consumer grade 1Gbps ethernet stuff you can see this now on a base debian install, where you need to enable the 'non-free' repo and install a .deb for a Broadcom provided driver to make a NIC work. Because their driver is considerably less freely licensed than Intel's. One of the reasons why I try to steer away from any Broadcom network interfaces whenever possible.

Or in any other category of hardware. With the current chip shortage and lack of viable competing options, it really sucks that there's literally two high performance GPU vendors that exist on the planet, Nvidia or AMD/ATI, and no other choices.