If stablecoin become a really big thing with hundred trillions dollar of market cap and there are large adoption of stablecoin pushed by governments, for sure defi will be a big thing.
It basically depends on how the adoption gonna happen to crypto, if adoption didn't increase, so does the adoption of defi to replace the tradfi.
But I can see defi becoming the future of finance, no more middle man that takes big chunk of value for nothing.
Well, most popular stablecoins are centralized. How would "De-Fi" stay decentralized this way? It would be more like "CeDeFi" (Centralized + Decentralized Finance) to me. Regulators have already won, bringing the single points of failure from traditional banking right into "De-Fi". Truly-decentralized "De-Fi" projects (if any) are scarce these days.
I'd say the future of "De-Fi" is dark. But I know many will disagree with me. To each their own. At least, Bitcoin is getting "De-Fi" features (via sidechains and L2). Therefore, not all hope is lost...