Do you know how many people use your product despite it being terrible? They use it only because there they invested their time when you came calling as the first mover and at that time, there was nothing like your product.
But the times are different now. First mover advantage is not as important if you continue being sloppy. There is an user of your product who is hacking away in her garage, building prototypes and sharing it with your community, a version of what your product should be.
If you get stuck in time, not killing your mediocre product in favor of building something your maturing users want, you have lost the battle already. It is only a matter of time before your position as a market leader is displaced.
First mover advantage is overrated because after a wow, if you stutter, it won’t mean much.