That's not career advice from Tyson, just an observation on human tendencies.
It's 100% right, and there's been analysis on how well many players do in their walk years before their paydays. We saw that here with Rendon and there's been many other cases of it.
Keibert has the 2nd highest pop time among qualifying MLB catchers, is near the bottom in arm strength, and unsurprisingly one of the worst throw out rates in the league. His negative defensive runs saved is a key contributor to the Nats being nearly the worst performers in the league by that measure.
He's 26 and either he can't improve, doesn't have the motivation to improve having been paid, or doesn't have the coaching to improve. Could be a mix of all three.