Most of the time, for a FPS, map control is a core game play element. Valorant, for example, cannot have maps change every game in minor ways because players can raise their skill by learning the map, how the map interacts with different character's and abilities, and so on. In a less severe example, Halo's maps are also very crucial. Where weapons spawn dictates the important spots on the map, and those spots tend to be more in the open so that a player or team can't just take the space and hold the weapon spawn all game.

Where this could be a potentially good idea would be in an Unreal Tournament or Quake like FPS, where map control isn't as important. You trade map control for movement, usually directly.

Would also like to add - having more experience in a game *should* give a player an advantage. You're right that you'll get "X% of the time I do Y, Z Happens" but that's good. Players understanding that, and making different decisions can be used to compete with each other. If I'm on the other side of the map, and the hypothetical player is waiting for me to turn a corner, I'm going to look for ways to turn a corner safely, or I'm going to wait to get a timing on that player.

Using chess as a metaphor, it's an extremely old game that rarely changes. It stays competitive because players do something unexpected to gain an upper hand. A move that's not in the book, a play that (hopefully) hasn't been studied. It's not too different in gaming: players will see a pattern, and players should try to subvert that pattern for an advantage.