Mint and Quicken are end user applications, Plaid is not. Plaid is an API provider to access financial information from multiple institutions.
When I wrote "how is it different" I meant how is it different in the task it performs which (I assume) Mint and Quicken also perform.
They later moved off of Yodlee to Intuit APIs, post acquisition, although those also do screen scraping [2], and thus carry the same risks.