Unfortunately the perception remains, but its been platform agnostic since like 2016.

I think it deserves some of the hate it gets for its previous state, but it is really a pleasure to work with these days.

My current job is a kotlin shop and I miss .net/c# a lot.

I mean... 2016 is pretty damn late

This hasn't been true for many years now, but that legacy persists in the popular consciousness.

Linux support is pretty good now. We only run it on Linux at work for web apps, works just as well as Node or whatever.

How about things like IDE and related development tools? Same level of support on Linux?

Rider (from JetBrains) is basically the go to IDE for most .net/c# devs I've met professionally. VisualStudio has come a long way but Rider is just chefs kiss.

And it is available on all platforms.

It used to use IIS express to run its applications locally (it has meh cross platform support) now it by default uses docker when bootstrapping a new application.

I've only ever developed for it on windows and very minimally on Linux, but I did not feel that the experience was worse on Linux.