Those aren’t exactly commissions. They’re an organizational and productivity scheme of the Legislative branches through which they subdivide work between sitting democratically elected legislators. If something makes it out of committee, it can make it to the floor, but no committee is committing legislative acts on its own.
There are Executive agencies called “commissions”, but they don’t have bonafide legislative power, so much as a scheme by which they try to reinterpret the legislation that authorized their existence and outlined their powers and jurisdiction to accumulate to themselves more authority such that a Court will occasionally step in and say “naw dawg”.