yes since more than 90% are scams, i think we should check each project we invest in. i mostly prefer to investigate dex-es with credible business model and interesting options for liquidity providers
but defi is more credible and transparent concept than ico and ieo was. u r right - there r a lot of scam project, and as for me dex-es are more interesting for trading and long term investment
besides i've found an interesting stablecoin exchange based on Curve - xsigma, do u know them?