Are you kidding? There are open source drivers for nearly everything on the desktop. The biggest holdout is nVidia, and that's for the same reason as Qualcomm -- they have inadequate competition. There are people who need CUDA which allows nVidia to shove proprietary drivers down their throats. And even that's slowly eroding as AMD comes out of the decade they spent asleep.

The problem with Qualcomm is that they keep buying every prospective competitor and the antitrust authorities haven't done anything to stop them, so there is no market pressure for them to do what the customers want because the customers have no alternative.

Custom kernels definitely aren't the only reason why the Android update situation is bad, but they're also definitely a nontrivial part of it. A hardline policy that kernel patches had to be pushed upstream if you wanted to brand as Android with Google Play would probably go a long way towards improving that situation for everyone.

Qualcomm would either say yes or all of their proprietary chips would become nonviable for the smartphone market.

Linux itself can't force that issue because they don't have an attractive brand and suite of basically mandatory proprietary services to take away from smartphone designers who say no. The only thing Linux can do is make life more hellish for people maintaining userland drivers, which companies don't care about because they're not interested in maintaining their stuff to begin with.

From the perspective of the hardware manufacturer, individual desktop linux users are worthless, and they're unable to form a large enough collective to have enough money to matter either.

Individual Android vendors may or may not be large enough to try and force the hand. Google requiring this as part of the Google Play contract, thus bringing a large number of Android manufacturers together, is a very different beast.

That said, there's still no way to know whether or not it would work, but comparing the collective phone manufacturers to desktop linux users doesn't really seem like a fair comparison.

Linux desktops remain a minority share. Linux mobiles account for the vast majority of smartphones in the world.

Or was that just a proposal?

They behave quite differently in what concerns providing drivers for ChromeOS or Windows.

That was a "soft forcing" which worked. Because nowadays there is almost no phone on the market which is incapable of working with GLONASS.

Of course you can overdo this, like (at least in the past?) Brazil did to push indigenous suppliers and markets, with the effect that they don't really have them, and everything "digital" is just more expensive.

But it could work. Depends...