I had a 2015 MacBook Air with 4 gb of ram, we just upgraded to a MacBook Pro with 16 gb. I felt the 16gb would make a worthwhile difference versus cost benefit for the 5 years or so we plan on keeping the machine as our primary computer. Based on our experience of the speed when doing one task versus several things open, I believe if we could upgrade the 4gb MacBook Air it would perform significantly better, so definitely felt the 16gb was a worthwhile upgrade to squeeze out some additional time and overall happier use for the machine when doing more than just the basics. I think there are many people who would be perfectly fine with a machine with 8gb of ram doing basic word processing, email, etc, but I think they'd actually be better off with a cheaper used computer in general. For anyone who even wants to do SOME iMovie, let alone something more advanced like FCP, even minor photo editing, or multiple browser tabs open at once, which is MANY MANY people, 16gb is helpful.