Contra anecdote: been using auto import with YNAB for years with multiple accounts and never had junk data. At least, not of that means the data is wrong/corrupt.

The two issues I have had:

1. Have to reauthorize bank connection, but that's Plaid's issue I guess.

2. Payee names are all over the place because it's often the merchant name. I used to try and fix these and only have a single page payee for each entity, but gave up.