That wasn't realistic until very recently, after Moore's law completely died off, but I hope it becomes the standard.
I have an X220 from 2011, i7 processor & 8 gigs of RAM. I payed 180euros for it (best deal I ever made, I know) and I hope I can get 10 other years from it. It chokes on modern uberbloated webapps, but hey, it's not like I want to use those anyway.
I built a gaming computer with an i5 and a gtx 1070 in 2016, and unless I decide to go for something else than 60fps & FHD resolution I still max out every game I play. I don't see myself upgrading in the next 3 years at least. Before that I had a crappy computer built out of low-range parts from 2010, and it was perfect until Dark Souls 3.