About the security content of iOS 15.8.5 and iPadOS 15.8.5

Not surprised. I met with Samsung for work purposes to buy hundreds of phone, and the best they could do with their flagship phones was offer 3 years of security updates. This was around 2019. Apple, who didn't meet with us, was around 6 years from our estimate.

From a ROI, for corporate phones, Apple iPhones had a longer lifespan, which is why we bought hundreds of iPhones, and not Androids.

On a personal note, I had the Nexus S, the Nexus 5, and they all died a horrible death either from lack of updates, or just having the physical button break, and the microphone stop working.

And let us not speak of Sony Xperia Z5, which all of sudden removed their fingerprint sensor due to a North American patent problem. They also broke their bluetooth audio so that song names STOPPED being displayed. That was all in a span of less than 3 years.

Never again Sony Android phones.

At that point, I got fed up of custom ROMS and joined the "iPhone, it just works" group and moved on.

"it just works" is the biggest lie they sell. It works only insofar as you use what 95+% of people use. Step outside and not only is it a big gamble, you've also got no way to debug anything. It's a world of walls and limitations with no Windows in sight

You seem to have hit all the bad luck and concluded (fairly) that anything but Apple must be bad. I seem to have hit all the bad luck on the Apple side. The device I got from work ran out of updates after fewer years than I privately use my Android, and not before the touchscreen partially broke, various apps had software issues that didn't manifest on other (identical) phones, the battery went bad, and certain OS features like hotspot didn't work half the time you tried to turn them on. I've simply never had these issues on Android, and if e.g. an app doesn't work, I can just wipe its data. On iOS there's no such button; it's not something you should need because in 95+% of cases "it just works" and so they don't let you. It's not your device

Currently I'm trying to help an Apple user whose email client broke, both on iOS and macOS, with unexplainable "could not connect" behavior that no other user is seeing (Windows, Android, and Linux all represented). It differs whether they use mobile data or WiFi, but in different ways on different OSes and email clients. Sometimes IMAP works partially (connecting, fetching mail, but not loading folders). I'll probably have to travel 90 minutes each way to see what I can debug on their device. They're tech savvy and we're both perplexed by the different behaviors but there isn't much you can see on iOS so we had given up on mobile email. Now that it's happening on macOS as well suddenly, maybe we can figure something out

It's just not a vendor I'd want to work with myself because there keep being major issues with very limited ways of fixing them. I'm sure most of the functions "just work", just like most Android phones "just work" and you hit a bad apple with that Sony device. At least on Sony you can install a different OS if the issues are major enough that people put in the effort of making one