Just to clarify, the the whole point is that Android makes it easy for less tech oriented people to host small single user / family services.
It does not need to be perfect, have massive throughput or allow for massive amounts of read/write cycles.
If people can host their own media server like Jellyfin or note taking apps like Joplin instead of using commercial services by simply installing an APK on an old phone they can leave connected at home, that's already a big win.
Regarding device longevity, Android 13 apparently supports / will support full KVM emulation. Windows can be run if you have root while android based VMs are expected to be possible without the need for root. Since this type of virtualization allows VMs to run their own kernel, keeping the "server app" updated should allow the user to be protected even if the host OS is outdated as long as these server-app-VMs are trustworthy themselves.