S,o are all the Popes the anti-Christ or just one in particular.
All...that’s the historic Protestant position held by nearly every major Protestant figure up until the early 20th century and held by many today. That position was held by many Christians before the Reformation as well.
By the way, if you are interested in understanding why Protestants held that belief, follow that link I posted and read what Wylie had to say. It can be read in one sitting because it’s more of a paper than book.