I stuck with Snow Leopard as long as possible, then Mavericks as long as possible, then El Cap, now High Sierra/Mojave.
Right now the only thing keeping me attached to the Mac is the ecosystem and the hardware, which is a sad state of affairs.
I jumped on the Mac with Panther because it was simply superior in every way to what the wintel world offered. Now apple seems to be abandoning the Mac at every step they can, and/or crippling it/making ****. And by **** I mean: the touchbar, all USB-C configurations, Photos, abandoning Dashboard, the terrible display server, no good replacement for Quicktime 7 Pro, slow core applications like Mail, a stupidly priced Mac Pro, the 2013 Mac Pro, no apple display offerings (the expensive beast is only recent and doesn’t count), removal of magsafe, removal of the startup chime, pushing this “post-PC” world (“what’s a computer”), lackluster adoption of new technology for personal computers (i.e. thin bezels on computers), abandoning “old” software support (iPhoto, iMovie, etc.), a myriad of bugs that are unacceptable for a PC operating system, and to top it all off there are rumblings of an architecture change from x86/x64 to ARM.
None of those points even mention the degradation of the intangibles: the mac no longer feels special, the hardware is boring and meh, the innovation is going away.