On NuGet.org there is only a very old System.Console
package targeting .NET Framework 4.6
but no one for .NET 6
.
Is this last version 4.3.1 from 2018 still valid for .NET 6
or is it part of another assembly?
System.Console
is built into the base framework for any project targetting Microsoft.NET.Sdk
in .NET 6 & 7 (and probably back to at least 3.1, but don't have anything open to check).
You don't need any additional dependencies for console output.