There are so many apps available to backup your data and they work the same on every Android phone, even one as old as this. Also not a good deal, you can get an LG G4 for the same money.
Well, some phones are better at backing up, as in easier and more reliable. With all the issues you’ve mentioned, the last thing you’d want is to add unreliable phone to the mix, just saying ;)
I'm sure some of the LG G3s suffered with bootloop problems as well.
I have this version of the phone, it works great. Only thing is the CPU is slow which is why I upgraded. If you don't mind a slow phone then this is as good as any others in terms of features i.e. the camera on the g3 is better than my nokia 8. Edit: oh and battery life was a lot less. Same capacity but I guess OS optimizations have come very far. G3 is one day use for me, my nokia 8 is 2-3
Yeah, better stick to other brands which never get lost, stolen or destroyed if you're the type who never backs up their important data.