"I'd like more competition in field X"
is functionally (game-theoretically) equivalent to the statement:
"I'd like to strip the current and future actors in field X of (some/most/all of) their power."
As an example, competition between states strips states, and especially those trying to use the state to gain their own goals of effectively all their power.
For instance...a state in close competition with other states that wants to prohibit abortion cannot. Mom can decamp to a nearby state with no such prohibition.
A state that wants a high marginal tax rate cannot. The rich folks move out...to lower marginal tax rate states.
A state that wants strong regulation on business cannot. The business moves to another state with lower regulation.
If you allow competition among barbers? Barbers have no power. If you allow competition among schools? Teachers lose their power. Very simple. Where there is competition, there is no power. Where there is no competition, there is power.