There will always be more ways for companies to extract value without contributing. Linus would have to continuously upgrade licenses from GPLV2 to V3 to Affero and so on. It is not really practical.

What Linus has contributed is already huge. We can't put all the burden of making the world right on him.

Like the industry wouldn't adapt to a more hostile license from linux? Huawei built their own OS, google has fuschia (and g* knows what else)

Would it be better if apple and google flipped the switch and made all future devices 100% closed sourced?

The likes of Microsoft, Apple, Sony and Nintendo already run kernels with less open licenses than Linux on their own devices. Others decided that maintaining their own kernel is too much.

So, what would Linux being more open really have changed?