Do not get me wrong, I hate Samsung as much as I hate any other large company, but I have to admit that this is quite classy. Galaxy S6 and S6 Edge have just received their January 2019 security update software versions G920FXXU6ESA1 and G925FXXU6ESA1: pretty impressive for smartphones released in on April 2015. This bodes well for the owners of Galaxy S7 and newer Samsung devices - it will be a long time before your smartphones will be so out of date that they will not be supported any longer.
MIUI 11 is coming out later this year. These are the phones that will support it