iOS used to be able to handle background tasks via very specific APIs, that started with iOS 4 and I believe this started to be reworked with iOS 7 and it behaves similar to Android in that background apps are suspended by default. According to an old video by Android Authority, iOS seems to be able to compress suspended apps down to a smaller memory footprint than Android. Both OS allow background services to run, but to my understanding iOS keeps way more control over that compared to Android (although vendor-specific battery saving features probably attempt to do something similar on Android). So in that way, it's still more specific/selective on iOS compared to Android. Prompt (iOS SSH app) uses the location service in the background to prevent iOS eventually killing active connections for example. Still, iOS seems to handle app suspension more efficient than Android (and yes, Android actually suspends background apps as well).

I'm with you that they could've likely bumped all soon-to-be-released iPhone 16 models to 16 GB, but rumors only have them at 8 GB. Makes "sense", as even the iPad Pro and MacBook Air still only come with 8 GB in their lowest configurations.

But I don't buy that them releasing the iPhone 15 with only 6 GB of RAM was a malicious attempt at limiting AI features. Seeing how unfinished their AI stuff is even in their latest beta releases, they were/are playing catchup. It was bad foresight and there are often talks about how internal teams at Apple are very secretive about projects in development, I wouldn't be surprised if the team developing the iPhone 15 knew pretty much nothing about the software plans with Apple Intelligence. It's still a very valid point of criticism though obviously, seeing as you could still buy an iPhone 15 to this day (it's still the "latest and greatest" non-Pro iPhone before the iPhone 16 releases in a few weeks) and you won't get the by far biggest feature of a software update releasing just weeks/months after your purchase. This is a huge step backwards in terms of software support, as iPhones normally get pretty much all major new software features for at least 3 years, and still most features of even newer OS releases (recent devices have seen support for major updates for 6+ years, the iPhone XS will get its 7th major iOS release with iOS 18).

I'm not saying "cut that poor multi-trillion dollar company a break", I'm just saying that not supporting the iPhone 15 for Apple Intelligence probably isn't a result of malicious acting, but rather bad foresight and poor internal communication. Limiting the soon-to-be-released iPhone 16 models to 8 GB on the other hand seems very greedy, especially with them trying to run as many of their AI models on-device.