Hmmm. I can understand the actors' concerns, and even sympathize with them, but what is to stop the studios creating entirely new faces / bodies to use as extras, or even main cast?
The technology isn't there yet, but you can bet that it will be, eventually. At that point, all those pesky organic extras who are causing disruption now are going to be "resting" permanently. This may not be a good time to annoy their employers!
As for complaining about the salary, well, it all about supply and demand, isn't it? There seem to be quite a few bit part actors - enough to keep the pay low. Apparently not so many folks with the technical skills required for the job, hence high pay. If you don't like the pay that other people get, perhaps a re-evaluation of your career choices might be in order?