Even then, most engineers of other disciplines do not need to be licensed. Safety-critical products must conform to standards and must be signed off by someone. Dozens or hundreds of other engineers of multiple disciplines can be involved in designing and manufacturing those products, but only one licensed engineer of any discipline is needed to sign off on its compliance.

Companies that have the kind of engineering culture required to produce safety-critical products already treat software engineers like any other engineering discipline and expect them to act with the same rigor has other engineers. That's actually why I cringe every time I hear about a Valley software company wanting to pivot or branch into products like that.