In South Korea I think the state invested in the entertainment industry, they can study drama at university. You can look it up on wiki. The agency system seems to provide a way for young entertainers to be supported, a bit like the old Hollywood system where you started out in B movies. There are some interviews on Youtube of entertainers that describe their experiences, positive and negative.
In the UK actors may do a degree, but a lot go to acting schools and then do theatre, if they are lucky they get in one of the big companies, so by the time they get on film they often have years of experience. It is only my opinion, that although sometimes you need someone who look the part, often US, Chinese dramas only want someone who looks good on camera, and often the scripts are poor, and they are doing them cheaply. Netflix spent about $14million an episode on The Crown.
The South Koreans seem to have found a balance of quality and quantity of output. It's going to be interesting to see how the world market affects their output. I like K drama because the scripts/stories are so diverse.
