This shouldn't be the case for .NET. You only have to download the tooling to build it (which can usually be done through package manager of your choice).

To run the built binaries, whether to require the runtime (by not including it in the executable) or not is a choice.

Tl;Dr of MSFT docs is:

    JIT (w/ Runtime): dotnet publish -c release -p:PublishSingleFile=true -p:PublishTrimmed=true
    JIT (w/o Runtime): dotnet publish -c release -p:PublishSingleFile=true --self-contained false
    AOT: dotnet publish -c release -p:PublishAot=true

These can be configured via .csproj properties too, there are multiple ways to set those depending on your needs. If you don't have any specific dynamically linked native dependencies included with your project, all of the options will be a single executable that you can just run. Do note that to use AOT on macOS you will need .NET 8 (right now it's RC1/preview).

In general, dotnet CLI commands are similar cargo (it had some of the features earlier, some later): dotnet new, build, add, publish, etc.

Right; to be honest I'm not a C# expert, I just did some stuff with RimWorld modding a while back, and when I did that I had to keep all that around for some tooling (specifically: ilspycmd) or it didn't work, but looks like I just couldn't figure it out. Checking my notes I used "dotnet tool install ilspycmd -g" with .NET 6 for this, but looks like I should have used "publish".

I've saved your comment here to look at if I go back to this in the future; thanks!