The other folks who lied to Congress won't be charged because they can't give information on higher ups in an investigation, simple as that.
This is reality here, not some ideal world. Mueller is investigating one set of possibilities and if charging Stone can get him information, he'll do it, obviously. What someone unrelated did that is similar, or worse, is not his purview, obviously.
The more concerning thing to me is whether FISA warrants were obtained illegally, and how often that has happened in the past.