When will support end for the iPhone 6+? Or has it already?

I am still using a 4s (unbelievable) after many failed attempts to migrate to my 6 Plus that I purchased new a few years ago. I am not able to upgrade to the latest ios on the 4s so many of my apps no longer function. Much of my contact data was lost and not synced correctly so I will have to manually cleanup hundreds of contacts. I have had an extended illness and would like to try migrating again now but do not want to waste my time if support has ended or will be ending in the near future for the 6 Plus model. It is quite frustrating that support ends fairly quickly on the new models that come out so frequently forcing you to buy new phones with ever increasing price tags! I am also extremely frustrated about how frequently the ios updates are pushed since I have lost data with these as well - it takes days of work every time an upgrade comes out. Managing a phone should not be this difficult!