According to the figures shared on the Compound website; There are more MakerDAO's fixed crypto DAI in the compound supply than in the world. However, it is not known how true the numbers reflect.
Liquidity on compound is moving significantly among assets as new rules are established for the release of the governance token COMP.
COMP and trading gain
Even if the DAI is borrowed and reinvested, it counts each DAI deposit as an additional gross supply. Users borrow and reinvest DAIs. Many users probably use several wallets to make this job easier.