It's the example that everybody uses, but because of the nature of vertical integration and the network effect, you can't use popularity as an indication that people actually want any given individual aspect of those products.

Suppose it's 2010 and you need an app that only exists on iPhone. Well, you might not like that it's locked down, but you need that app. Then once you've had one for three years you're locked into their ecosystem indefinitely.

It's also a trap. When the lockdown first comes, they say they're just using it to exclude malware and other things you actually don't want. You have to get your apps signed, but they sign all the ones you care about, so what does it matter?

Only after mobile platforms that don't do this have reached negligible market share and have no network effect do they start excluding apps you might actually want. But by then it's too late.