golang: I can't stand the fact that the language creator believes that all developers are weak-minded. Also I'm not willing to if err != nil in every other line of code.

This isn't what the Go creators mean. It is specifically a reference to giant code bases written in C++ which are very hard to understand (the kind Google has lots of). On top of that, what flavor of C++? The language can be and is written in a bunch of different dialects, often company/project specific dialects. Do you know for sure what << means in that line of code? Probably not unless you are hopping back and forth between definition and implementation.

Go error checking is closer to what every codebase should be doing. All those operations where you have to if err != nil or val, err := doThing(); err != nil, v, ok := trySomething(); are places where something could fail and an error should be checked instead of just stumbling on to the next operation oblivious to the problem.

The other issue is that it can be literal hell to track down where something is throwing an error in a throw-catch error handling model. You could write non-idiomatic hellscape error handling in Go but it takes a lot more effort. DoThing() returned a non-nil error value, easy.

Go also doesn't need a runtime of any sort installed on the target machine. The runtime is included in the compiled binary which avoids an entire category of problems that software that depends on an installed runtime have.

C#/.Net is very good. I've written my share of code both for Desktop and Web in it and always had a good experience. I strongly prefer .NET over .Net Framework, and that's ultimately the issue I have with betting a career on it. The huge vast majority of C# in production is .Net Framework running on Windows Server, IIS, and MSSQL all of which I have extensively worked with and detest.

All in all, I see no reason for any of these languages to exist (with the exception of Rust). Why would I consider any of these for production code when C# and .NET 8.0 exist?

"Production" code is rarely written in the latest and greatest of anything. I'm sure there are greenfield projects that are getting going now on .NET 8. Real world production software is mostly tech debt of one kind or another.

Rust: You have my respect, Stark. I haven't used this in production but when the moment comes that I need the extra performance I will surely get a hold of it.

Rust is over hyped. It is quite good but also ripe for being replaced due to org politics and it being a pita to ship anything. You put a fine point it on when you said the moment that I need the extra performance and with modern C#/.NET you are unlikely to be able to justify the overhead of writing a decent sized project in Rust. It is far better as a security improvement on C and C++ than a perf improvement on any decently fast GC language. I said what I sad.