You are right, trust is the most important thing here. But nordigen does not want my money for their service. Instead they want to sell what looks like APIs for ML over your transaction data. So they at least have a good incentive to use my data for training their model.

ofc, I dont know what they do with it, they may be cool ethical ppl just doing a cool thing and my mistrust might be totaly misplaced.

But I have to trust another entity that proxies my connections. Another link in the chain.

And I dont really want to hit on nordigen here, as I said, I dont know them, I have not read that whole website and havent looked in the details.

For me its more about the generell problem. I find it sad that a service like this seems nessassary.