One of my goals is to not share any data with a company I can’t trust – so I write my own tools for all these purposes, my own apps, and self-host these things.
I already have a several GB large archive of my mail as I self-host it, why shouldn’t I be able to write software to parse it and remind me?
Why do I always have to use services of a company when I buy a device, instead of being able to hack together my own?
When you bought IBM PCs, they didn’t force you to use Windows with Notepad either – instead, people could write Linux, GNU, and Emacs for their own usage.
This is what I expect from an open system, like Android.
Unfortunately, it's really the chipset builders and the lack of UEFI/BIOS or something similar in ARM (and other non-x86 mobile platforms) that locks it out even further.
And having to write my own smartlock provider as a system app isn't great either.
It'd be great if in addition to everything being AOSP, they'd also allow changing more at runtime.