The major concern here would seem to be the fact that old and/or cheap Android devices tend to… leave something to be desired… when it comes to security; and in ways that aren’t readily fixed short of a full firmware upgrade that they will never receive because their blobby BSPs have been completely abandoned and certainly never upstreamed.
They might not get to your laptop; but with an internet connection camera-and-mic widget running a worm farm available your privacy is unlikely to win.
I’m not sure why there doesn’t seem to be any vendor of lousy SoCs that realizes that maybe they could move more units by playing nice(it’s not as though the Raspberry Pi won on performance or cost; it’s the alarming fact that Broadcomm is actually atypically friendly by the hellish standards of the genre); but until that happens including a burner phone in your security plan seems risky.
