Apple

What? You can root pixel phones, nothing is locked down on androids

Also removing the microSD slot from the flagship phones.

I used to laugh at how the Apple was the only manufacturer that forced you to pay $200 for every $15 worth of storage. Not much to laugh about anymore since Android flagships keep insisting on copying & pasting Apple’s militant anti-consumerism.

implemented measures to prevent rooting/customization

This part isn't true. Google Pixels (just like Nexus) are the only Androids out there (other than Fairphone) that allow you to sign and re-lock the bootloader after installing Calyx or Graphene. And you can even install Graphene using webUSB now.

That said, I agree on the rest. While Apple was adding CardDAV and CalDAV, true NFC support, shortcuts, and SMB, Androids were dumbing-down its interface, and removing the 3.5mm jack and the dedicated fingerprint scanners.

Now iPhones have USB C, and iOS will be getting sideloading. All I have left to miss is the back button, notification panel, GBoard, and ability to turn off blocking animations.

Android alienated its power users to (fail) to court iPhone users, while Apple successfully did the opposite, courting power users. It's worse recent sins are removing force-touch and the SIM slot.

I watched a video recently which also said that reasons for Android losing ground to Apple is that the products have become more like each other. Android used to be seen as the cheap alternative to the expensive iPhone. But nowadays flagship Androids are just as expensive, if not moreso, than flagship iPhones. Apple also offer a much cheaper version of the iPhone which is comparable in price to low-to-mid-level Androids. Not to mention the fact that the longer OS support of Apple means that buying a cheap second-hand iPhone is easier and easier.

Couple that with the fact that, as you say, Androids are becoming less customisable while iPhones are becoming more customisable, and all the reasons that people used to choose Android are becoming less and less true and/or relevant.

Don’t forget the selling of your data.

I miss the rooting/jailbreaking days it was fun to learn how the software and hardware functioned in unison with each other why side loads would or wouldn't work. And honestly most the stuff that people consider cool or just take for granted on the iPhone now or only available through jailbreaks on the earlier models!

Google has locked down Android, implemented measures to prevent rooting/customization

True that, especially with Samsung. The last time I read, Samsung has some sort of "e-fuse" in their security chip that destroys itself if you install an unauthorised OS version and voids your warranty, blocks Samsung Pay, and blocks their "Secure Folder" feature. At least Samsung has Goodlock. Which is blocked from running on my phone (a Samsung M52, so it is faster than newer Samsungs that support Goodlock).

made all their apps a constant A/B/C/D test controlled by server-side flags that constantly rearrange your UIs and prevent the ability to sideload specific app versions

Is this specific to Google's implementation of the Android UI? This isn't an issue on my Samsung.

been less generous with the free service offerings, and repeatedly shut down, re-launch, re-brand, and overhaul all their apps and services.

True that, that's why the only Google services I use (besides ones my university requires) are YT, Gmail, Maps, and Play Store.

I got tired of all that treatment after years and years of using different types of Android devices. The update scenario didn't help either, even though Samsung has done massive strides to improve in that aspect.

That is so true!!! Constant ui changes in google apps are fucking infuriating. One day for 24 hours I even had COMPLETELY missing watch later playlist on YouTube and I use it all the time.