Why isn't DeFi adopted on a wider scale?

Hello friends)

On one hand I can understand that the original idea of DeFi is quite far from what we have now. All these regulations confront decentralization and anonymity for regular users, I know that. But on the other hand, taking into account how DeFi services function in real life, DeFi integration with our financial infrastructure can result in money savings for financial institutions. And as a result it can make the prices on goods and services cheaper for us. In “Future of Post Trade” by Deloitte 80%-85% (it’s about $3.2bn) of post-trade settlement expenses can be saved by utilizing Distributed ledger technology. That also doesn't include savings on AML, KYC, and so on. If we consider these, savings will be even higher. And it seems like a nice tool to make our financial relations easier and cheaper.

So, all in all, I want to figure this out. Is it all technologically difficult to implement? Or is it because of politics? Maybe I missed something else here, will wait to read the opinions/facts on that from you guys.

I’ll link here the doc I studied https://www2.deloitte.com/content/dam/Deloitte/us/Documents/financial-services/future-of-post-trade.pdf