Catalina
As I don't own an iPad or iPhone, is there any point in upgrading. I am very happy with mojave?
iMac 21.5″, macOS 10.14
It´s usually a good idea to upgrade Macs to the latest OS. Having said that if you're happy with Mojave (as I am!) and use a lot of 32 bit apps then I would first check to see if you can update these apps so they'll run under Catalina, as only 64 bit apps will work with Catalina! If you have an external SSD you could install Catalina on it, boot from it and play around with it, leaving Mojave untouched on your internal drive. Hope this helps you! Regards, Ian.