Macs will run both Windows and (with some EFI hacking) Linux. It's true that you need a Mac to (legally) run macOS, but that's lock-out, not lock-in. Essentially it is a $1000 license to the OS and perpetual updates.
I meant that if I my standard workflows and software are on MacOS, then I'm locked in to a single hardware provider and their offering.
For some cases this is a limitation. Their laptops are quite nice and the imacs are okay, but if I want to have, say, a powerful desktop workstation with a bunch of nvidia GPUs for CUDA then MacPro doesn't really cut it, and I'll have to run Linux on it; and if I need a extra secondary/tertiary computer/laptop that doesn't really need to be good, then I have to choose between it running a different UI than the main computers or paying a rather hefty premium because of the lockin.
Macs will run both Windows and (with some EFI hacking) Linux. It's true that you need a Mac to (legally) run macOS, but that's lock-out, not lock-in. Essentially it is a $1000 license to the OS and perpetual updates.