The thing is, in this case we HAVE a solid pictures of every alternative. There's no speculation necessary. We have the "before" and "after" story to point to, and we even have the "alternate universe" story along with it.

Before Android and iOS, the phone ecosystem was pretty mature already. There was more os-level diversity but a lot less choice. It was just half a dozen utterly crappy worlds of lock-in, with barriers to entry that kept newcomers strictly out, and removed any hint of incentive for the incumbents to improve their platform. Remember everything was SO BAD that blackberry actually looked good in comparison? It was practically a parody of monopolistic inflexibility. Regardless of platform, everyone universally hated their phone with such passion that it was a meme in its own right.

Google and Apple both poured a boatload of money into each making a phone platform people would actually like to use. That alone was revolutionary. But each company showed their philosophy in how they presented it:

In the Apple case, the iPhone was shiny and proprietary and carefully presented and DONT TOUCH THAT. You couldn't even write apps for it. You could have web pages, that was enough for you.

In the Google case, Android was open and messy and unconstrained. It wasn't locked down an any meaningful sense; Google originally just kept some basic control of their branding and their marketplace. But without rules, carriers went back to their old tricks, and the ecosystem started to crumble. Remember that almost nobody but Google ever ships "Android", every carrier and manufacturer ships their own fork of Android. And for a long while they were all pretty bloody awful as everyone in the supply chain tried to extract value with preloaded apps, ads, lock-in features, crap hardware, and egregious branding. So using their only leverage (the play store), Google has slowly and carefully been pulling Android back from the brink.

Ironically, sadly, it's exactly these actions Google took to save Android that the EU objects to. They can't see (they refuse to see) the whole picture; they just see the tiny bits they think are relevant. They're like a nearsighted sleuth who finds blood on the floor in a hospital, and arrests the first nurse they see for the murder of persons unspecified. Whatever you say of the evidence they found, they clearly don't even begin to understand the environment.

As for the two companies and their strategies: For Apple, their phone very literally saved the company from demise. They make so much money from selling iPhone hardware that nothing else they do is even important. For Google, going the "open" route with Android wasn't the strategic commercial miracle we like to pretend. But if (and only if) you look at Android as an investment in the future of their Search business, then you can justify the ongoing expense. If you think of how much money it _could_ cost Google in ads revenue to have Apple or Amazon monopolize and manipulate the market, now you've got something huge.

Android can't survive on its own. There's nothing even there to survive; it's not a business. But it can be part of the search and ads business. That's where it can find a niche.

Remember that Android was, and remains today, the ONLY successful open-source consumer operating system, ever. There isn't even a runner-up. Nothing. This is not a business model with legs.