My 2 (to 4) cents:
I agree that it's player-dependent.
I've never bought into many of the theories espoused here as if they're gospel, the social media distracting one being one of them.
To generalize, a Kyrgios or a Tomic would have found distractions in any era, and the best of the best (okay, Big 3, but many others as well) would have succeeded in any era.
People kill Tsitsipas for his social media posts, but how long does it take to make a post? People here presumably hold down jobs and post here (seemingly 24/7. People...even elite tennis players...have always had some free time; it's just easier now to do it in the public eye -- or harder to escape it now. Again, how long does it take to post something on social media? Should that player, instead, be living, eating and breathing tennis 24/7? That's ludicrous.
"We" take little bits of Info, and apply it without proportionality.
Although he's somewhat private, we know that Rafa owns a huge yacht, loves to fish, and hang out with his longtime friends and play video games. If he had gone into a slump, is that the reason? Or, because he shot...I don't know...an underwear commercial?
There were players in the 80s who somewhat notoriously hung out at clubs like Studio 54. Wasn't that a whole lot more distracting than making Instagram posts?
It gets beyond silly. Other than tennis, I mostly follow American team sports. Take the NFL. Let's say Aaron Rodgers is having a bad game (I'm a fan, and he just had one), and seemingly, every commercial break, you see him on his State Farm (insurance) commercials. People act like he's shooting those commercials live during the games. "Damn, if he weren't so busy shooting those ___-in' commercials, the Packers would be winning."
I tend to think that players (in general) are just as committed to the game as they always have been, but they do have free time and, you know, lives as well.