I read that windows support for .rar, .gz, .7z and other archive formats only comes next year.
Isn't the CLI already available though? I recall reading that it was made available in Windows 10.
Doesn't support compression though, only decompression. Something to do with RAR licencing I believe.
That's a feature IMHO. Openness and interoperability is a bare minimum requirement for a general purpose archive format. RAR doesn't meet those requirements, so we'd benefit by having less people creating and distributing them.