A couple reasons off the top of my head: * YT has been good enough * Barriers to entry are high * Video requires tons of bandwidth (expensive) * Youtube is

A couple reasons off the top of my head: * YT has been good enough * Barriers to entry are high * Video requires tons of bandwidth (expensive) * Youtube is already integrated well with many devices * It's difficult to make a profit (YT only recently became profitable) Not saying it's impossible by any means. Just that it would be difficult to surpass YT to gain traction AND make a profit.