I think this is accurate.Surfing better waves is the only bona fide pathway to improve as you get older.
I'm Slater vintage and I feel my good wave surfing with dialled in boards is still improving.
Getting your boards dialed and figuring out what you like and don't like is a big part of the equation.
And anyone who has ever been on a good waves surf trip knows who quickly you improved (followed by the drop-off again once you return home).
Realistically here in CA you can go many sessions without getting a decent wave, and by that I mean a wave that allows for at least 3 real turns.