Steam's Deadlock just "officially announced" and "released"...in alpha...CLOSED alpha. You need an invite.
There are currently 55k people playing, with a peak of 64k. Heck, Deadlock had 30k before it was even announced.
Concord still (on Steam) hasn't cracked seven...hundred. Didn't even crack five hundred today, and is currently under three hundred on Steam.
Out of sick curiosity, I just did another comparison. CoD: Black Ops 3 (from 2015) still has 6k+ people playing at the moment, with a daily high of almost 10k. A game from 2015 has more than 20x the players, and 18x the daily peak.
And this is all despite ad campaigns plastering Concord banners everywhere. I don't recall ever seeing a launch quite this bad. I don't even know how they did it.
2k peaks, looks like