I was given just this statement at face value, but I think it refers to nucleophilic reactions where the carbonyl is the electrophile.
From what I understand, the $\ce{-OR}$ in ester is more electron donating inductively than the $\ce{-OH}$ in $\ce{-COOH}$ (due to the alkyl groups in $\ce{-OR}$). So this should make the carbonyl carbon less positive, making it a weaker electrophile, making it less reactive no?
The resources I read say that it's because the $\ce{-OR}$ is a better leaving group than $\ce{-OH}$. But alkoxide ($\ce{RO-}$) is a stronger base than hydroxide ($\ce{OH-}$), so why would it leave first?