Pinta VS MonoDevelop

Try pinta, which is basically a linux port of paint.net. A little more complicated than what you seem to be asking for, as it incorporates layers, but it's a lot easier to get your head around than gimp. Plus the layers come in super handy if you're doing anything slightly complicated involving combining images.

Pinta is an open-source cross-platform fork of Paint.NET, now running on .NET6.

You are right, there is now fork named Pinta: https://github.com/PintaProject/Pinta

An older version of the underlying source code remains available: https://github.com/mono/monodevelop

From what I understand MonoDevelop has been discontinued. Even their repo has been archived.

SharpDevelop and MonoDevelop are both dead and focused for devs which gives them different priority than apps targeted at non-devs, but they show how to put together seriously complex apps, and they're the ancestor of the Visual Studio for Mac.

Monodevelop

There are Linux binaries for MonoDevelop which is what VS for Mac is based on.

Using Visual Studio with Wine is not really possible. But you have other IDEs as options. You can pack Visual Studio Code with the needed plugins. You can use MonoDevelop which is the IDE from the Mono project https://www.monodevelop.com/. Something to add here, the Mono project is actually developed by Microsoft. And there is Jetbrains Rider, I personally use it every day at work and am kind of in love, but it costs you 139 € in the first year.