OpenSUSE on Desktop, macOS for laptop. Iβve used macOS on portables for years now but only in the last 3ish months have I gone the linux Desktop.
As to the βwhyβ - macOS because itβs polished, tightly integrated with the hardware, the ecosystem works harmoniously, itβs secure and Unix-based (Darwin is the name of the base OS used for both macOS and iOS).
For Desktop - I used Windows pretty much all my life but itβs gradually turned into a bloated advertising and tracking engine. Iβm speaking as a home user and a 10+ year IT professional. Linux has come in leaps and bounds and OpenSUSE is an enterprise-grade OS that also happens to run games and other personal things nicely. If I wasnβt using it Iβd probably be using Red Hat but I dumped it largely due to their shitty business practices.