Mostly based on the airport IME. At LGB it is nearly ubiquitous. Pretty sure BUR sees it sometimes, too.

It is very unlikely at JFK, save for the occasional international hard stand arrival.

The vast majority of airports do not offer it as they have jet bridges to the terminal. The only time I recall consistent dual door deplaning where a jet bridge exists is the old DL Shuttle at LGA (10ish years ago; no idea if they still do it today). With open seating I'd always sit at the back door and be in the taxi line before those in row 1.