Auster

I check sites that list hardware specs, and once I find a phone that seems interesting for an average price I’m willing to pay, I check places like XDA to know how much of a hassle it’ll be to unlock the bootloader and add a custom ROM. And if modding the phone has too many/too big drawbacks, I return to the first step until I find a phone that seems good.

Never understood why repeating the last word from the top text at the bottom is done in some memes.

On that matter, if you haven’t dug on the topic yet and if I may suggest, look for Linux systems (“distros”) with either the Xfce or Wayland desktop environments, since they’re some of the lightest around (Xfce being the most stable of the two, but Wayland seems pretty promising already).

If you absolutely must get something from Google Play, I suggest Aurora Store, which acts as an alternative frontend for Google Play, so you don’t have to have GApps installed.

If you have use for command line programs, Termux, a terminal emulator, is a great option, and it also works with root.

For reading eBooks, I also have a recommendation, Librera Reader (but I’ll check the OP’s recommendation too).

Material Files and Simple File Manager are great file browsing tools. But if you need a file browser for root specifically, I recommend Material Files specifically.