And now you have to rely on a framework, where there's more opportunity for leaky abstractions, more surface area where bugs can show up.

I'm not sure what you mean by complex data - data is data, and using a serial format like edn allows you to encode a lot of different stuff as data - even functions. I think you're stuck in the oo mode where you're passing around objects and classes instead of just data. Data is so much easier to deal with!