There is no universe in which Unity is a show case for “why should we pick c#?”
The engine is C++, the C# integration is bad, the new ECS translates C# to C++ (or some cpp like IR) before it runs, and the whole thing is closed source and openly hostile to open source (eg. package managers) that might damage their revenue from the asset store.
Don’t get me wrong; modern C# projects are pretty cool, but this is way cooler than Unity.
Burst and IL2CPP are different things. Burst is also a different “can’t believe it’s not c#” custom layer they invented, own and now have to maintain a separate fork of.
(Apparently just maintaining IL2CPP wasn’t keeping them busy enough)
If you're talking about Burst then it would be more correct to say they added another language that is similar to but different than C#. AOT Burst builds a native library so I don't believe there's a C++ step.
“ I'll say that our goal is to keep up to date with modern .NET. Once we can get Unity synced up, we will continue to push the latest .NET features to Unity. So we want to bring all of these features discussed to Unity developers, and find the best ones to use in the Unity API.” (1)
Ie. no. It’s not done. No one knows when it’ll be done.
If you’re really keen, just read that whole thread and you’ll get a really good understanding of how great things are, how happy with the c# support everyone is.
Tldr: netstandard 2.0 != .net 7 and nuget support.