But don't all those date fields have date pickers that ensure that the date is entered in the correct format?
They do, if you care to use them, just as the old ones did.
But they are also text entry fields, and should function properly as such. Or, if we want to regress further, be disabled for manual entry so users must use the pickers.
IMO, hitting tab to the field and typing a date is faster/easier than using a mouse driven date picker.