What are your thoughts about financial agreggators that store your bank passwords like Plaid and Teller.io?

I'm an independent developer and I'm considering building an app, initially for personal use only, using a financial data agreggator like Plaid or Teller.io. These store your username and password information (with exception of a few institutional for which Plaid supports OAuth).

Specifically I'd like to hear opinions about Teller.io since it's a smaller company. When asked the CEO said this: "Although we are smaller than Plaid, in my opinion we are more technically sophisticated than they are. Not only …

app bank building cybersecurity data developer financial financial data information oauth password passwords personal plaid store thoughts username