As someone who uses visual studio + code literally every day, I'm not sure what you're referring to with most of these complaints.
The project/solution files are bog standard xml, and well documented, but in general you shouldn't need to touch them.
The migration from framework to core 3.0 is now very simple thanks to xaml support, but it used to be a huge hassle. You can literally just edit the tags in your csproj/fsproj/etc to enable different target frameworks, or you can use the ui [0], and then you'll need to do a nuget reinstall. One command [1].
As for running into bugs, they built bug/feature requests into the visual studio 2019 ide, or you can access it via the website [2]. They are usually very responsive, typically something within a couple of days.
[0] https://stackoverflow.com/questions/57334018/visual-studio-2...
[1] open package manager console, type 'update-package -reinstall'.
[2] https://developercommunity.visualstudio.com