First of all, Nvidia Shield was launched with Android 5, we are now on Android 11, so you are wrong if this it's your point. In this case, @lexluthermiester hit the spot.If you have to ask the question, then there is no help for you. Try Google, or anyone that has owned the same Android phone for more than a year.
On the other hand, as @Flying Fish said, Samsung, Google or others Android, even Nokia, are upgraded over almost three years, five on recent phones, so I'll suggest to buy a phone from companies that offers a better support.