For example, they put in place a firewall to ensure that Motorola wouldn't have any advantages over other Android manufacturers. I don't expect them to do that again.
That being said, major acquisitions are hard and I expect it to fail once again. But they'll mostly make different mistakes rather than the same ones they made last time.
Actually that sounds good, we could do with a third viable handset OS, but that's a digression and at this point a bit of a fantasy. They have nowhere else to go.
Back in the early days of iOS and Android the consensus seemed to be that the smartphone OSes were pretty much done. To compete with iOS all you had to do was match it's features, or catch up, and once you had it was pretty much all over. Since then Apple and Google have constantly found compelling new features for the OSes almost every year. Apple is sinking billions into the development of iOS, just look at what they're doing just in the area of health[1], and there is clear blue water in terms of quality and features[2] between it and Android, and that gap is increasing.
Google makes most of it's money in mobile off the iOS platform, yet is investing hugely in Android development and making a pittance out of it. Not only is that unsustainable, but if they really want to compete with Apple they need to dramatically increase their investment in Android. They only way they can justify doing that is to actually start making significant revenue off Android. The only way to do that is to sell their own handsets, differentiate them from competing Android handset vendors, command a decent profit margin and grab significant market share.
[1] https://www.cultofmac.com/316559/abc-news-goes-inside-apples...
[2] Super robust and secure XPC; Superior power management; Custom development tools, languages and hardware-software integration with things like Metal and the motion co-processor; High quality health and fitness tracking; VRKit; Highly consistent calibration of sensors between devices, vital for precision applications like VR; All this is arguable in the details, sure, but the fact that Apple is spending hugely on this backed by blockbuster revenues isn't and Google can't realistically match that just for the heck of it. They need a revenue stream to back it up.
So no, Google do not make tens of billions a year off Android. They may possibly make a profit off of it of a few bn a year, but that's about the best we can say. On the other hand they pay Apple $3bn a year just to be the default search engine in Mobile Safari. That's how big the gulf is in the mobile market between them and Apple. They make about 4x as much money off iOS as they do off their own operating system. If I was running Google there's no way I'd consider that acceptable, because all that iOS revenue is at Apple's discretion.
Android is too big. The oems are too invested. They need Google. Google on the other hand, could flip the switch one day and say that they do not need them anymore.
Pretty good deal IMO.
As they were doing that I remember thinking "these phones don't make much sense for Motorola in terms of generating a profit, but they make perfect sense for Google in terms of blanketing the world with Android phones."
I'd say Google was quite happy with what they were able to do while they had Motorola.
It's likely and possible that the patents were the primary purpose for the acquisition. But they put too much money & effort into the handset business to suggest that they never intended to make a go of it.
In a scale that big, "2.5 years later" counts as immediate.