What I see is not over yet, because in my opinion this trend has just started considering that almost all blockchain platform projects has dived into DeFi. Initially this trend started from ethereum, then I don't know why others seem to follow, and what is currently being discussed is polkadot because there are so many "swap" projects that has sprung up and I think in the future a lot of DeFi will be created using Polkadot, for example this new dex swap is becoming hype.