It all depends upon the manufacturer. Given that the most current Android OS is in the 7 range, chances are strong that any device still in the 5 range will be staying right where it is.
Verizon Wireless has a page that gives devices, OS and date of last update.
Android units are usually updated for two years. Windows mobile devices vary (although Microsoft has said 2019 is the end of the line for W10M). iPhones are supported longer.
Given the vast number of computers running Windows XP, Microsoft supported the OS for a very long time. Interestingly enough, some computers running XP are still being used today.
Dexman I read that you could upgrade (not updates) to android 6 if you are using 5 if and when they stop updating 5..? Kinda like the way win 10 is supposed to be now it just upgrades.
If Google and LG wished to upgrade the device to Marshmallow, an update would be pushed to Verizon Wireless. While there are workarounds, officially, the lack of an update means that the end of the line has been reached.
Thanks everyone guess it still boils down to buyer beware. Since I did not know that there were OS on cell phones that could become outdated,I bought the phone I bought .At least when you buy a computer they are up front as to the OS on it. Here you have to load each phones specs separately to see what OS is loaded.Then go back and forth to see which phone has which OS on it.
They should let you search for a phone with the OS being a filter then your looking at only phones loaded with that OS like buying a computer.
The compare function is worthless unless you know the OS in the first place.
Like Kathy said it would probably still be usable without updates just not secure for data saved on it.