For a decent dev tool under Linux - what about MonoDevelop? VSCode looks ok, but I haven't tried the Linux version, but apparently you can do C# development in it.
I'm not really up to speed with C# dev these days, last job I had which required C# was 2009, and since then I really haven't done much serious development in it (It's 95% Delphi professionally, and Python for my own stuff)
Edit: I wanted to re-iterate, I absolutely love Python Tools for Visual Studio. Those guys have created (what I have found to be) the highest quality python development tool I have experienced. The downside is it requires Visual Studio. If they can take what they have added to VS, and re-produce that in VSCode.... Wow, I would be very happy.
As for the IDE Intellij IDEA rocks and has a community edition.