Yes, there's always been a bit of alpha-nerd posturing in RPGs. That's how I mainly see that sort of behavior - the boasting about dominating builds, about "winning" at D&D, boasting about doing the most damage - all casting their bid in the competition to be alpha-nerd.
"My Damage Per Round is BIGGER THAN YOURS!"
There are lots of people who play D&D for power fantasy. Some of them define that in the crudest terms: if we fight, I will beat you up. Some want power over the external foes (monsters, villains) and some want to establish that they are the BIGGEST at the table, by comparison if not by direct PvP.
WOW is an influence towards superbuilds and calculating damage with decimal points, but D&D began as a variation within miniature wargaming; emphasis on dominating the battlefield was built into D&D before it was even published under that name.
Personally, I was quite happy in the sessions when my bard cast Faerie Fire, and the Advantage helped the fighters and barbarians get more hits, and the players of those fighters and barbarians recognized that my character was contributing to DPR. If there had been no inter-player recognition, though, I would have been less happy.
And then, after the fight, when it was time to get clues from captured foes: my bard had Detect Thoughts plus high Persuasion, so the bard got clues, and that was also a spotlight moment.
I'm not about having THE MOST, I'm just about having enough.