I disagree with your last statement. Is promising to change not evidence of the motivation to change?
Some people lie about their intentions or don’t plan to change as quickly as expected, absolutely. But to assume everyone who has promised to change won’t feels unfair.
I get your point that it’s not specifically Chrome or specifically Safari that are holding other browsers back, but Apple and Google own the vast majority of market share in mobile devices and by extension, browsers used in mobile devices. I think that’s the crux of what the investigation is getting at