This happens on most Android phones, including my Google Pixel with 8gb of RAM. I noticed that it starts doing this when battery drops below 50%. Which is weird because it surely takes more resources (and thus drains more battery) to cold start an app every time instead of just keeping it in memory (provided that app doesn’t do anything nefarious in background which is easy to detect). There is plenty of RAM for that.
It seems to be fully backwards-compatible with standard JPEG. I.e. image viewers will that don’t support newer formats will display it as if it was a JPEG file with SDR colors.
Also, HEIF/HEIC is patented format that you need to pay royalties for. Open formats are obviously superior and there are multiple ones that support HDR (there is also open variant of HEIF that uses AV1 encoding but I don’t know whether Android or iOS support it).
Not only Google services. If you want to make a phone you need to buy SoC from Qualcomm or MediaTek and all the drivers for it are proprietary (often including Linux kernel modifications). Sure you can technically make your own but it’s impossible for 99% of phone makers.
Some apps can’t even be disabled (including via adb).
Well, yes, it’s a business decision. Google wanted to push their Chromecast devices so they made them use proprietary Google Cast protocol and removed Miracast from Android (both phones and TVs). They later added Chromecast/Google Cast to Android TV but it is still not supported on other platforms. Samsung on the other hand had their own TVs which don’t use Android TV so they added Miracast back to their phones and removed Chromecast so that their consumers would buy Samsung TVs.
Those are different words.