Back in the old days they didn't have CGI, so the entire story casmwacrried by the actors and their portrayal of the characters.. there was no crutch.. no safety net etc.. lot more pressure on them to deliver an outstanding performance, because the success of the movie depended on it..
These days most movies seem to be driven by CGI with backup roles by actors.. there are some very talented ones, but I don't think most movies depend on them as much..
BUT..
Acting methods and whatnot have evolved and improved over the years, so..... hopefully you see where I'm going.. so KIND of a wash.. but..
I do think actors from the B/w days were all around better actors..they had to be..
Friendship is like peeing your pants.. Everybody can see it, but only you can feel the warmth..