Sure, there are plenty of people born these days who presumably have the capacity for genius of the greats of the past. And yes, the sheer number of scientists working today, with access to knowledge and facilities far beyond what was available centuries ago is producing a stream of research and increased scientific understanding that is far greater than it's ever been. None of that invalidates the hypothesis (which is all I'd call it) that there'd potentially be more stand-out geniuses if we didn't live in a world with so many distractions available in devices we carry around with us all the time.
Wait. How can you disentangle the distractions of the world we live in from the result that there are more top-tier people working today? Saying that the variables are independent isn't enough. I'd say that the null hypothesis is that great communications technology is the root cause of both distractions and more 'geniuses'. You can't have one without the other to my eyes.
It's a testable hypothesis if you can get enough people to agree that their kids should be banned access to all such distractions (and such a ban to remain in place into adulthood). Obviously they'd still need access to electronically available information. Whether discussion forums/messaging apps count as distractions might be a grey area.
I honestly don't know what the result would be, or how long it would take to determine the outcome one way or another.
I mean, theoretically, yeah. You could do the test if you had some sort of absolute tyranny over people, a ton of money, about 1000 babies to otherwise do nothing else with, staff to raise those babies according to the experiment, and the 20-35 years of time to wait for the experiment to conclude. I'm sure I'm forgetting some crucial variable to control for though.
But that test is never going to be run. Nobody has that kind of time, that kind of money, that lack of morals, nor that energy to devote to this. There isn't a review board on the planet that would allow for this to occur, for good reason.
Agreed, it's not practical or particularly realistic - I don't think 1000 would be enough either. Maybe 50k? I'm not sure we'd like the results we might get either!