The young man doing 24 accents of English in this video is in fact a remarkably talented dialect mimic.
Ignore the dull and self-deprecative 60-second introduction and the obligatory apologies for personal or ethnic offense (his accent clips generally involve some choice obscenities and a few stereotypes). Yes, there are slips that reveal where his command of a dialect is shaky (he is not good on Jamaican, and not all that good on American English). But don't obsess on those. If you've heard a few British and Commonwealth dialects, you will see that he gets a lot of things spot on. This is a young person with some real career options in front of him: actor, comedian, impressionist, broadcaster, voiceover man, spy, confidence trickster, or even (oh, let it be, let it be!) linguist teaching phonetics and phonology?