Yeah, agreed. I'm very reluctant to do unnecessary things to my phone and computers too. In addition to an Ardruino, I have a second tower (my older system) around for doge-coin mining and other experiments.
The last "hack" I did to a mobile device was my old Nook Color, which I had bought specifically because it was a cheap way to get into the then-new tablet world. Android tablets were still kinda crappy back in 2010, as well as expensive. $250 was able to get me most of what made a decent Android tablet at the time. It could even handle a lot of the graphics heavy games available then, and I only missed a microphone and a GPS (bluetooth was enabled by Cyanogen Mod)
Since then, I've had less and less of a reason to bother. Regarding mobile, every company appears to pay close attention to the customer. Additionally, everything is more polished and cheaper than it used to be.