If talking about non proprietary kernels' drivers, such as linux, then again, profit is what regulates it. No wonder why now nvidia finally cares about linux, being the most used kernels behind the cloud, behind servers of whatever. Meaning, it's not profitable not to support linux now a days for Nvidia.

The other fundamental factor is lock-in, which is abused by some big corps, such as MS.

But the profit idea es even wrong, but it's what we have been educated with. For an OEM, providing FOSS drivers or FOSS FW doesn't mean to have less profit, but somehow it's interpreted as such. And there's also our culture, backed by corps again, that tends to make us believe that everything profitable enough has to be corporate secret, and if not, others would take advantage of you business. That way of thinking really prevents for more FOSS adoption at the OEMs level. I don't agree with it. It might be the presence or lack of some HW features might be inferred by the drivers/FW, but it doesn't mean your competitors will know how exactly you provide such feature, and even less how to make it with the performance you do. And usually once released, you really want to show off your features, your innovation and so on, not keep it secret. So in general, really see no issue for OEMs not to offer drivers and FW as FOSS, even as free/libre SW.

I can imagine OEMs offering FOSS drivers and FW, but that not being as convenient for the major players in the market, since that would risk their position in the market. Just a thought...

Remember the lock-in mechanisms by the corps that feel being threatened if open sourcing dirvers... Some of which no longer say it out loud, but still think GPLed licences are a cancer...