This isn't completely true. lsb-release contains everything that is in os-release, including the version of the distro in a neutral format.

However I agree with you that lsb-release is not much used, and in some distros is only present when some huge X-dependent LSB package is installed.

But hey, we could fix LSB! Instead of, you know, making up something new that will be as little used as lsb-release.