They don't have to share it unless they release their changed binaries.

The GPL is no less commercially friendly than the MIT, given it allows commercial usage, and explicitly protects commercial usage.

Funny that every company I've worked at is ok with MIT and won't touch GPL with a 10 foot pole.

Please don't make these dismissals, there are many companies that make tons of money off of GPL software. The GPL purposefully disallows anyone adding restrictions to the code that would cripple commercial use. It's fine if your company doesn't want to comply with its terms, you don't have to use that software. But just remember that the GPL is not meant to pander to companies that intend to take the code, lock it up in a proprietary product and never give anything back to the community.

The GPL's very nature cripples commercial use because a very large number of companies rely on being able to control distribution, or need to participate in markets where distribution requirements cannot be met if the GPL is used. Good luck navigating the specifics of deploying GPL tainted software on a closed down app store or a console for example. Companies don't have any obligation to 'give back to the community', and I'm not arguing on whether anyone thinks that is fair. The GPL is commercially-friendly in a very very narrow set of examples. Imo, to call it 'commercial friendly' in a general sense especially within the context of other FOSS licenses is insincere.

The distribution controls and market requirements are unfortunate, but if they are being imposed on you by a platform owner then it's that vendor's fault. Those app store agreements are absolutely loaded with commercial restrictions. Please don't pin the blame for this on copyleft licensing, when those vendors have explicitly decided they were against it long ago and would do everything they could to stop it including banning it from their platforms in an effort to destroy the commercial viability of what they view as competition.