Unlike DeFi platforms which have tokens, the centralized ones have to find people to lend to. The tokens skew econ of the lending platforms with many lending for the sole reason to get the "mined" tokens. And like you said lending has thus been dried from the centralized ones with many people just using defi products for those sick yields. Ideally, all these token mining "hype" has to end soon to see a more realistic volume for DeFi but idk when lol. Might take a bear season of no hype to see a more realistic view