Since Green is the Color of ramp, Mono-Green Commander decks often are able to maintain their mana and easily ramp into their key cards
Nicol Bolas brings about concessions more than most cards I have found
Impeccable Timing deals three damage to an attacking or blocking creature, which can be used to turn the tides on an otherwise disadvantageous attack
Aesi, Tyrant of Gyre StraitAesi, Tyrant of Gyre Strait might be the worst offender, simply allowing you to play a land, draw a card, and then play another land to draw another card
If you dont have a land to discard then you cant retrace, and if you dont have the mana available then you cant retrace
Bannings in more competitive formats are much more impactful, and no Commander players who were interested in the card had a chance to purchase one yet