It first became blatant/noticeable to me during those marvel netflix shows. Not during Daredevil bc they did a smart (and plot-relevant) job of covering half of Charlie Cox's face in every fight scene, long before he even had the full suit made. He could swap in and out inconspicuously with the stuntman and we'd never "know".
But when it came to Iron Fist... lol. They couldn't hide that, and the show suffered. Basically, as they moved towards "everyday man" if not "pretty boy" actors to play action-star roles, naturally they came across the dilemma that barely any of those muthafukkas had ever thrown a punch in their life.
At the same time, Tony Jaa and those guys from the Raid can barely speak English... so it'd be a struggle to cast them in most American films other than as the silent super henchmen trope, like what they did with that Indian martial artist (from RRR?) in the "Grey Man" movie.
That said, we've seen OGs like Denzel, Keanu, a prime Matt Damon, etc., take the time to learn the craft to become believable (non-traditional) action stars.