"Out Of Combat," was the context.
However often that may be.
In the specific example of a group stealth check, though it's just a very late fix to a broken sub-system. Sneaking past something is a common trope in genre, but the way D&D handled it was untenable, from the early days when Thieves had to roll both hide in shadows and move silently or specific races got a better surprise check, and, either way, only alone, through the contested stealth vs perception checks of 3.5, group stealth was both virtually impossible, and held up as an example of "smart play" - a Group Check vs a DC finally enabled the trope.
Works for a few other things, too. And it's nice that 5e, in its orgy of recidivism, didn't do away with the mechanic, just because 4e introduced it.
But, that's the 30 seconds of resolving some dice rolls, not the 5-10 min of discussion that's the bulk of non-combat play in D&D, so not relevant, as I understand the argument.
Though, this last example sounds more like the fighter /is/ the challenge to be overcome by cooperative play.