The good thing is, on Android you can get an APK without root or anything like that, same for installing it, and you can use an emulator (or something like waydroid) to run it on a computer. For cases where the game doesn't use any more specialized servers, and just uses the app store for authentication, DRM, etc. the situation is no different from PC games with DRM - it's bypassable, and if done right, will work for all games, not just one.
That said though, it's very true for multiplayer/always online games, and those are very common on mobile. While it's possible to reverse engineer and rewrite the servers, for most of them nobody is going to bother. And in the world of aggressively monetized games, developers have an incentive to keep it that way - they can't make money from players who are still enjoying a game they've already squeezed every penny out of.
And reinstalling the packages, moving over all the configs, setting up the partitions and moving the data over? (Not in this order, of course)
Cloning a drive would just require you to plug both the old and new to the same machine, boot up (probably from a live image to avoid issues), running a command and waiting until it finishes. Then maybe fixing up the fstab and reinstalling the bootloader, but those are things you need to do to install the system anyways.
I think the reason you'd want to reinstall is to save time, or get a clean slate without any past config mistakes you've already forgotten about, which I've done for that very reason, especially since it was still my first, and less experienced, install.