You have 3 years to evaluate the market and see if it makes sense for you to do so. Given the events of the last 10 years, the landscape won’t be the same as today and none of us know if that will be better or worse for your specific situation.
Buying now could make sense ONLY when your bank would give you a lower interest rate on a used car loan than your current MF is. Which is very unlikely.
His point is that you’re trading an interest rate (rental charge/MF) for another (financing the lease buyout).
Why would you take the risk of a potential increase in car prices at this moment? If the market value goes up, them you take action. Your lease buyout won’t change.