If your workflow benefits from the speed it quickly pays for itself when factoring in developer salaries here in the US. I recently switched companies and they bought me an M5 Max 128GB as my dev machine.
Builds and local test runs are 3 times faster than the Windows laptop option. The machine will pay for itself just based on that within 3 months. I can spin up a local kubernetes cluster and do full integration tests while I am working on other things as well.
It isn’t a strictly Mac vs Windows thing though. It looks like the culprit is the MDM software on the Windows machines is just crazy slow and constantly getting in the way.
If I was paid less it would definitely make less sense for the company to pay for this machine.
Don't worry. Once IT Security discovers that they miss their trusty endpoint security products on your Mac, they'll add it and you'll be in the same ballpark as the Windows machine. Been there, received that, and learnt that Microsoft Defender exists for macOS, too.
That's why you gotta have your work laptop, and your "work" laptop. Give them something to secure. It makes them feel important.
Gosh, the last sentence is the most terrifying thing I’ve read today.