It's important to remember that the commissioner serves at the behest of the owners.
Yes, but leadership is still a massive factor. The commish serves the owners, but when you have 30 guys in different situations all with the day-to-day of their corporate empires; and the commish dealing with the day-to-day of league-wide business... there's still a massive gap between someone who's reactive and someone's who pro-active; and who has a narrow field of vision based on "this is what we did before" vs someone who sees every angle and the ramifications of each.
You want a guy who's like "This dude plays 3D chess" and not someone who sees only two options. We judge a commissioner by how they REACT to things, but the tenure of commisioners are really defined by the PROACTIVE leadership.
Manfred is reacting to a lot of things quite well: COVID. RSN crisis. "Three-outcomes baseball" being sped up. He is reacting to Oakland and Tampa poorly, with "aw shucks, what can we do? Root for the Giants I guess."
But his proactive things are atrocious: Moving Houston to AL and year round interleague play and playing everyone once. And reorganizing the minors.
Those are examples of "ideas with strong merit behind them" but making decisions as a reactionary and not a visionary. Is it better than now? Yes, let's do it. (Moving Houston).
A visionary says "well, what's the ideal way? Can we do that? How close to that can we get?"
A visionary says "it SOUNDS good on paper, but what's the ramifications?" (play everyone once).
Selig's reaction to things was not very good, but his proactive things were largely fantastic. Unifying umpires and league business (the massive screwup of the SF/OAK typo not withstanding), and most importantly, proactively starting MLBAM, adding BILLIONS of revenue to the league.