> they don't follow platform guidelines

Do platforms even follow their own guidelines? And if they do, are those guidelines good? Microsoft doesn't seem to care about UI/UX at all, Apple's UI/UX quality gets worse each year, and Linux is all over the place with each distro doing its own thing. What guidelines are those apps supposed to follow?

Looking at the current state of things, I think it's good that apps tend to do whatever they think is best for their use case. Also, most people don't switch between 100 different apps all the time.