It's, more or less, practically impossible to be OS agnostic for a backend with any sort of complexity. You can choose layers that try to abstract the OS layer away but sooner or later you're going to run into part of the abstraction that leaks. That plus the specialty nature of Windows/Mac hosting means your backend is gonna run on Linux.
It made sense at one point to use Macs but these days pretty much everything is electron or web based or has a Linux native binary. IMHO backend developers should use x64 linux. That's what your code is running on and using something different locally is just inviting problems.
The problem of course being that x86 linux on laptops is still and might always be terrible. Using an ARM Mac to develop your backend services is not ideal but probably still a better user experience than the 0.01% where a modern language does something vastly different on your local machine than in production (which is btw also very often ARM these days, at least on AWS).
I've used Ubuntu, WSL2 and currently a M1 mac and if I need to be mobile AT ALL with the machine I chose a Mac any day. For a desktop computer Ubuntu works great though
It made sense at one point to use Macs but these days pretty much everything is electron or web based or has a Linux native binary. IMHO backend developers should use x64 linux. That's what your code is running on and using something different locally is just inviting problems.