"For example, the dicta creating the presumptively lawful restrictions on bans on felons, mentally ill, etc. There is no constitutional basis for those, they were not the issue before the court, and poof! SCOTUS created them out of thin air."
The SCOTUS didn't "create" anything by that statement. The restrictions referred to already existed. ALL the SCOTUS statement said and meant was, "These other firearms laws are to be presumed lawful until such time as they are reviewed by a court. We're not here to discuss those other laws today, so we will not do so."