(The same can be said of many problems, both very serious problems and not so serious ones.)
Would ending casting by "type" mean that people of various racial and ethnic heritages would continue to get jobs? Would they cast an African American woman as the girl next door that the handsome blond guy was mooning over? One would hope so, but maybe, maybe not.
We tend to think of some people as creative. But, even apart from the diversity issue, white actors have long complained that they got cast, if at all, only in one type of role, usually the one they played when they first came to the attention of the industry in a big way. Hero, villain, tough guy, muscle man, seducer, victim, goody two shoes, glamor figure, clumsy buffoon, etc. So, maybe casting directors aren't that creative. Maybe they aren't going to consider, let alone send out a casting call for, an Asian or African American actor to play an "ordinary" American.
In the old days, this might have been the kind of issue the Screen Actors Guild would have been willing to take on. But the screen writers strike a few years back resulted in the writers losing a huge amount of pay while getting next to nothing in bargaining. It also resulted in lots of TV money going to reality shows from that day to this, instead of to scripted shows. So that was a huge lesson to the entertainment industry about striking. Plus, the success of such strikes depends on big names either joining the picket lines or at least refusing to cross them. That didn't happen during the writers' strike either. Didn't even happen when liberal show hosts, like Maddow, crossed picket lines to get into the studio to air their shows.