Yeah, there’s been a lot of this and it’s totally true, but only to a certain point.
Compare to an athlete. There’s going to be a point where they reach peak performance, whatever that looks like for them and they won’t physically improve any more regardless of how much they train. Any training at that point is predominantly maintenance.
Performance quality can improve by experience and strategy, maybe equipment improvements. But your physical condition has peaked.
It’s the same with writing. At some point, you just can’t get any faster. You can get better though. You can always get better.
Good thoughts. 👍