I wonder why Android can't have some bigger improvements to it. Google has a lot of developer resources, and some items added might make it a lot more developer and enterprise friendly:
A hypervisor comes to mind, so Android can have a VM for work, a VM for home, etc. This is especially useful with dual-SIM phones, or a phone using the SIM for one VM, and Google Voice for another.
A filesystem like APFS with deduplication, bit rot protection, encryption provisions on a block level, and other items.
A way to have nandroid built into the OS, so not just /data, but the entire phone, ROM, apps, and stored stuff can be dumped out as a backup. This would make life a lot easier should an OTA update cause a bricking.
The ability to scale down the OS to fit on phones 4+ years old, and work well (as in run all existing apps.) If Windows, which is an OS far more complex, can do this, it would be useful if Android could run on devices with far fewer CPUs/RAM/storage, as there is a big market for lower end Android devices, especially as the economy worsens.
The ability to do containerization.
The ability to do OTA updates as compressed diffs, so even if /system was modified, updates can still take.