This question already has an answer here:
I have not seen anything document in in the rules stating that a feat is an extraodinary ability.
I have seen it being categorised as a 'special feature' of the character.
This question has already been asked but with no RAW satisfactory answers IMO. Has anyone really looked through all the core books, index words, the FAQ, Sage Advice, and Rules of the Game resources with no indications at all what feats as special abilities are categorised as?