Buddhism:

Unlike many religions, Buddhism has no single central text that is universally referred to by all traditions. However, some scholars have referred to the Vinaya Pitaka and the first four Nikayas of the Sutta Pitaka as the common core of all Buddhist traditions.[page needed] This could be considered misleading, as Mahāyāna considers these merely a preliminary, and not a core, teaching. The Tibetan Buddhists have not even translated most of the āgamas (though theoretically they recognize them) and they play no part in the religious life of either clergy or laity in China and Japan. Other scholars say there is no universally accepted common core. The size and complexity of the Buddhist canons have been seen by some (including Buddhist social reformer Babasaheb Ambedkar) as presenting barriers to the wider understanding of Buddhist philosophy.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". What has been seen by some as a hinderance to understanding Buddhist philosophy?
size and complexity of the Buddhist canons