I'm not going to Catalina. I have far too many 32-bit things running, all of which work perfectly. That includes some hardware-related code, for example the driver for my Unitor MIDI interface. It all works now, so why break it? And as far as I know, there are no 64-bit drivers for the Unitor. I also have several 32-bit plugins, utilities, etc. And they all work. I'm even putting off buying a nice shiny powerful new iMac for the same reason - it comes with Catalina.
I'm currently very productive with the iMac I have, so the golden rule for me is - if it ain't broke, don't fix it...!
I should add that my iMac is almost 11 years old, and running High Sierra.