igortyhon, Do you know how long you stay saved? or is it just lost using LocalStorage if the player uninstalls the app?
I have not been interested in this issue, on mobile devices definitely more than a month.
The problem is that some players have all sorts of cleaners and optimizers and they can sometimes clean the records and players then swear.
Another common problem is that on the web some players use privacy-oriented browsers and then wonder why nothing is saved.
But even if you do nothing, the percentage of such cases is small, but they are upset and shout the loudest, so on popular games I re-dub the save to the cloud.