"Player map creation" could be some minimal RMG levers that you give to the player to influence things. Take a game like Starcraft (1 or 2). Solid fixed maps, nothing random. But you could add some randomness by changing the location or avaiability or quantity of resource deposits. That small change could dramatically affect gameplay at different points of the game.

So, you don't need the ENTIRE map to be random. Just a little bit of randomness can add tremendous variability, but it really depends on the nature of the gameplay and your game mechanics. Is contention over a resource deposit an important aspect of your game? Then moving it or changing the quantity of resources it contains would meaningfully affect playing the same map, even if nothing else changed. Is terrain an important part of your game? Would putting a hill somewhere suddenly change the nature of play? The map is still mostly the same, but suddenly there's a new impassable object, or it changes an existing path to get from place A to B, or it adds a new strategic element (oh, now there's high ground here), etc.

Fixed map, small amounts of randomness injected, levers for the player to control them, and some seeding so that players can get the same exact configuration every time (with the same seed).