There are actually several people from Mozilla working on it. Now there's
help from Cisco too and others. So while there's an army of people working on
it, it'll still take years. Opus had people from Mozilla, Microsoft,
Broadcom, and etc. and despite that army of people it still took five years
of full-time work from all of those people.
HEVC/H.265 is not a magical beast that is merely breathed into existence:
Work on what would become that codec can be traced back to 2004 (so in that
case we're talking like 11 years) so, as you can see, developing a codec is a
very long process with lots of work. I think you don't fully grok the amount
of work that is involved here. :)
Finally, to be sure we're all on the same page, please don't expect to see
Daala itself ever completed and released. Rather, that work is being folded
into NetVC along with Cisco's Thor codec. So keep your eye on NetVC. :)