I think it's perfectly reasonable to require firmware be open-source or permissively licensed to customers. It's pretty rare that firmware is a competitive advantage; companies just try to produce the bare minimum to get their devices to work and maybe lock them down to sell software subscriptions.

If you sell me a piece of hardware, you should owe me any software required to make it perform to its original spec. Simple as that.

The canonical wisdom is that the more security sensitive or critical a piece of software is, the more important it is that it be auditable. Open Source meets that criterium, and is arguably the only thing that does so fully.

Some systems do require secrets, that's what cryptography is for. The algorithms are generally open and audited, and only the minimum (the keys) are kept secret.

Both ideas make sense.

Wouldn't mind ALL firmware, but also clearly some device categories are also more crucial than others.

>Would you say the same about OHV firmware? Airplane firmware? Cubesat firmware? Amateur rocketry firmware? Starship firmware? Speedgun firmware? BGP router firmware? Consumer Wifi router firmware? Any wifi firmware? iPhone firmware? GPU firmware?

Yes.