The dude fear mongering about DM's clearly doesn't know how much shit a DM has to put up with when his party is really interested in the tangent of how thicc that goblin was.
The purpose of the DM is to make the game fun for the party and prepare the game. That's it. Not make sure the story progresses not force anything to happen. Just to make sure the game is fun for the players and make sure there is material to use if it's called for.
I'm not saying dumb tangents aren't funny, but not every DM enjoys it when his game is brought to screeching halt every time the party collectively begins a open mic moment for five minutes or more after something funny happens,
But never, have I seen D+D.
https://www.chick.com/reading/tracts/0046/0046_01.asp