I have a PowerMac 7300 (1997) on OS 8.6, still running, but slow; a G5 (2005) with Tiger (non-Intel), also still running when needed; one 2009 MacBook with El Capitan and new SSD hard drive; and a 2015 iMac.

i will not be upgrading to Catalina (I have been testing it). When these give up the ghost I think I might call it quits; much as I love Macs, I have no time for the way Apple is now working and the latest very expensive MacPro.