Because we are more socially interconnected, so the strings of society that keep us connected are also the ones constraining us. The "risk" of non-uniformity outweighs the gain for most people.

Back then, doing something that society deemes risky/provocative/condemns, as an artist, a musician, a politician would be seen or heard only by the people present, everyone else would have second or third hand accounts of it, and that would be maybe tomorrow, maybe the week after, maybe the month after.

You could get drunk in a tavern, get in a brawl and paint the owner's wife posing as a nude boar. The people who would know about it first hand would be only the people who directly saw it. Your boss wouldn't hear about it unless he is in direct contact with the people there, which would be rare.

Nowadays, getting in a brawl would end up with someone calling the cops immediately, someone posting it on instagram, someone calling your job to get you fired with probably a dozen articles next day "drunken fool fights local bar owner after insulting his wife".

These social constraints, the speed of information and the interconnectedness of it all is constraining us into uniformity, as behaviour against the graph is more and more ostracised - unless you have enough social capital to afford it, at which point it is rewarded.

So of course we are less interesting - we are being forced into uniformity.