The text uses a paradox, a statement that might at first appear to be contradictory, but that may in fact contain some truth.
Nobody goes there anymore: it's too crowded at first appears to be contradictory, because if no one goes to the restaurant, then the restaurant should be empty, not crowded. However, it contains some truth: if a restaurant is frequently perceived to be too crowded, many people will no longer want to go there.
Which figure of speech is used in this text?
Rebecca's Bistro used to be a great place to go for a delicious and carefully prepared dinner, but nobody goes there anymore: it's too crowded.
A: apostrophe
B: paradox