That’s nice, usually I do 3 years with a phone. So if I did not buy it on day 1, I run a security risk in my pants.
No, because as long as updates come out, you can also install it on your phone. If you buy the device later than release, you usually get the device (exceptions left there, of course …) with the latest software already on it. So this kite does not go all out. It can only become a problem after that three years, but that is not so long anymore, if you buy a new phone every 3 years.
In addition, you can prevent a lot of problems yourself, by paying attention and using wit when you visit a site, or when the phone suddenly comes up with a message to install / download a particular app to name some examples. If you do not trust it, you can also take action yourself.
Samsung would naturally adorn it, if they release the source code of several drivers for a change, so that the custom ROM community can continue with the support itself.