I can't comment on the Florida routes, but as far as I know Norwegian are the only budget airline operating long haul flights to LA. If they were actually that cheap both Skyscanner my travel department would be making me use them.
As for Oakland - that's really a business destination in Silicon Valley. Same for nearby San Jose which BA recently restarted flights to. I expect plenty of high value business travellers on both of those routes, benefitting from the fact the Silicon Valley has terrible infrastructure and horrible traffic problems, meaning that flying even a few miles closer to your destination can significantly reduce travel time.
Looking at their route map and their fleet of planes, isn't Air Asia a short haul airline? They only have A320s at the moment with some A321s on order. If the numbers on Wikipedia are correct, they have only 80 planes (compare with 363 for Ryanair) so are a relatively small player. I see they are also deferring aircraft orders, so presumably they are growing more slowly than expected.
We will see. I also expected Ryanair et al to start budget long haul flights. I'm sure that lack of aircraft doesn't help but the long haul business model is also very different to short haul and I suspect it doesn't transfer very well.