I totally disagree. While Microsoft is adding new features to C# (and .net in general) at a fast clip - this is a good thing. It shows they are still investing in it - it is not dead but rather very active. You do not have to use all the new features - in fact you can completely ignore them if you want to.

I do most of the time - I still write properties the old way for example.

I care more about my tech stack adding new things than staying the same - the industry is going that fast that does matter. It I will not see it as a negative unless they deprecate the old ways of doing things - and they aren't.

C# and .net today are in a place that I could not have even dreamed about when I first started with C# in 2003. Its totally cross platform, has excellent mobile support, and with Blazor Wasm finally we have the promise of .net everywhere without custom plugins.

Everyone has the right to choose there tech stack - and I have found only more and more reasons to stay on .net - not less.

Microsoft's new CEO has spearheaded all of this - he is the best thing to happen to Microsoft in a long time (Steve Ballmer was the worst).

p.s. I am not a Microsoft fanboy. I use the best tools for what I need. I use macOS as my daily operating system where I do the majority of my development, MacBook pro to run it, LG 5k screen on an arm, AWS for cloud because it is the most consistent and stable while still innovating with new things, .net and C# for my tech stack, sqlite and mysql for db's, Slack for team communication, Aeron chair because I work at my desk 9-10 hours a day, and finally Microsoft Natural Keyboard and Ergonomic mouse because I don't want carpal tunnel syndrome (and because of this I have never had it despite a 19 year career in software engineering).

Bottomline - use whats best for you, but C# is not dying by any stretch of the imagination.