Yeah "publish" is magical, I specifically jumped from .net 4.8 to 5 just for this feature.
msbuild had publish since at least .net 3.5 (when I started to use the platform) it was just a little bit akward to use tough. and of course dotnet publish is 1000x better than msbuild with it's obscure syntax (which got way better in .net5 and 6 with -p: syntax, etc.)
-p:Property=Value (or /p: Property=Value) has existed in Ms build since the beginning. That's not a .NET 5 or 6 thing.
Also If I'm not mistaken most of the properties (if not all) can be set through the command-line (for good and bad :)), e.g. `set Property=Value && msbuild` or `Property=Value msbuild` (on unix systems)
One thing though, is that native .dlls are still outside (DetoursServices.dll for example in BuildXL). But still pretty impressive what it can done. That, and the new embedded .pdb (for .NET only, e.g. not native).
I wish "publish" was used more by the place I work for (most of the folks would simply Release (F5) and store what's there in p4). I've only recently discovered about "publish" and that is after haven't worked with .NET for so long...