But I agree. .NET will not replace Java or any other serious language.
I think you have to specify a domain to make that statement reasonable. I think .NET is used more than Go for example. Maybe more than NodeJs also for server systems. Less than Java. If we compare to C++ it is very much down to domains. I don't hear about many enterprises using C++ for server backend code but of course they exist. And so on. .NET (or C#) may already be "leading" against a lot of other languages and then the question is if the others will replace C# or not. And if it will take some of the market from languages like Java which I think it will but not all.
Basically what everyone usually advocates as "Python" in performance critical stuff, but we get the the productivity and JIT/AOT tooling from Java/.NET eco-system as well.
SharePoint and Sitecore are .NET Framework only. Only CSOM is Core and Sitecore just released their first Core support last month, and most enterprise projects ends up plugging into them.
Forms, WPF still have issues running on top of core, UWP is stuck on Core 2.1 compatibility and .NET 5 is focused on desktop deployments with UWP future uncertain.
It’s pretty much as far away from “serious language” as it’s possible to get, but here you are happily using it anyway.
Take your Gatekeeping and get in the sea, thanks
The beauty of Java is that it is like C, plenty of implementations to choose from. :)
Yet I don't see .NET getting on Java turf as much as many Internet thinks it can.
It remains mostly a Windows stack (so many enterprise third party are yet to release Core stuff that is actually cross platform), and there are plenty of platforms without any kind of .NET support, yet you will find a Java vendor on them.
Also ironically Microsoft is now a OpenJDK member and they are the ones doing the Apple Silicon support.