Samsung does not release monthly updates for three year old Galaxy S6
And although your phone is indeed a greater risk in terms of security, there are so many other people who also walk around with an “unsafe” phone (no source, personal experience from family / friends and family).
And a large part of that family and friends who do have an iPhone do not have it because they choose the longer security updates, they prefer no updates because they only cost space and it “seems” as if it is getting slower. With this I want to say that a large part of the people do not care about the ball or receive updates.
And of course, the beauty of Android is that you do not necessarily have the version of Android that Samsung puts on it.
These are my findings and opinions. Of course you do not have to agree with this, and I really do not want to defend Samsung, because I would also like to have a longer update policy, of course, but I want more, but you can not have everything.