I don't think the sensors really matter for a server but the rest makes some sense.

Still, 80 bucks will buy you quite literally a Mini-PC (a really crummy one, granted) which can run more server tasks because it has as much or more memory and storage and isn't hindered by there being an Android OS layer there doing nothing useful, and which is absolutelly and 100% under your control because it boots into your OS of choice.

Half than that will buy you a crummy SBC which probably de facto has as much capability to run server tasks as that Oneplus (it's weaker but doesn't have Android there eating up resources) though in my experience those things tend to be a bit finicky.

I don't think it's actually worth it to spend $80 on an used phone to use as a server (unless you do need UPS-like features or built-in mobile nertwork access) since you quite literally have better options brand new for that money, but if you have one around it can make sense even if it's a bit more work getting it going and is not fully under your control (unless we're talking about something jailbroken where you can install Oxygen or Lineage on, so a Pixel would probably be a better choice).

That said, there is a certain technical elegance in the whole notion of repurposing an Android Phone to be a home server.