Many years back, I bought an expensive android phone to discover that it did not support my native language. I have the necessary technical skills to add support for it, but because the phone was locked down (something enabled by permissive licenses but not the GPL), I couldn't fix the phone myself and ended up with a very expensive but useless brick.

Corporate interests rarely align completely with your own, and this small difference can be very damaging to your interests. The GPL, while not perfect, alleviates some of the damage caused by this misalignment by ensuring that users remain in a position to address it.

The problem is, in practice, the GPL doesn't assure as many rights to the user as it is claimed. The example of Android shows this clearly. While the base of Android is GPL and consequently freely available, nonetheless Google managed to mix it with enough proprietary parts, so that they could could block Huawai from selling their phones with Android. Of course, Huawai is able to build their own OS based on the open source parts of Android, but for all practical purposes it will be a separate OS.

Only the kernel is GPL, AOSP is Apache.

Well, right. Thats my point. They have enough parts in "Android" which don't fall under GPL and thus they can keep them proprietary.

"the GPL is ineffective because the non-GPL parts become proprietary" doesn't seem like a strong argument against the superiority of the GPL.

You are not getting my point. The point was, that the ability of the GPL to enforce source sharing is limited. Where source sharing and redistribution are not desired, GPL licensed software just isn't used. Or used in a way that it does not affect the propriatary parts.

The whole argument of Stallman is that you don't give companies the choice to use permissively licensed software (by making it economically impossible for them to rewrite the entire body of free software).

I think "there isn't enough software under the GPL" is not a criticism of the GPL's effectiveness. If anything it supports the GPL as a method for ensuring user freedom.

If the only open source software available to companies were GPLed software, they would not switch their product to GPL, but rather not use open source software. GPL isn't making companies share source which they don't want to share, they just avoid anything GPL. That is what I meant with the limited powers of GPL.

This isn't about not wanting to "give back" to the community, companies using permissive licensed software are contributing back. It is about that the GPL is incompatible with the business model of all companies which are licensing (selling) the software they produce.