As someone who played with ETH and DeFi on 2021, the potential seems to be there.
But the fees killed it. You want to deposit your crypto at in a dApp and earn interest? You pay to permission the dApp to spend the crypto (each crypto), then you pay for the actual transaction, then you pay when you want to change the balance or claim the rewards or withdraw. Often times fees are $5-10/apiece pending how high demand is and how intensive the transactions are in computing power.
The way they fixed this? Via multiple layer 2 solutions that didn't talk with one another and required another set of hefty fees (at the time) to get onto and off of along with 5-10 day type settlement periods.
Pair this with rug pulls, unscrupulous actors, hacks of legitimate dApps, and legit dApps that just seized activities forcing you to transact, it was too much to navigate while prices were falling 90+%.
I think things have improved slightly since then, but not enough to get me re interested. ETH ecosystem seems roughly the same as it did 3 years ago, but BTC has continued to power forward.