I’ll also note that point-by-point refutation of even specious arguments sharpens the mind. It might not look like a muscle, but if you don’t use it, you lose it.
Personally, I like to use the analogy of dojo practice. If you expect to progress to black-belt someday, you’ve gotta spend time sparring.
P.S. Anyone who has practiced martial arts knows that the dojo is very much a “safe space” — in that there are mats on the floor and certain basic protective gear is required (groin-cups for men and mouth-guards for everyone, at a minimum), and there are expert teachers refereeing the whole thing. It just happens to be a “safe space” where the whole point is to punch, kick, and/or hip-throw each other, and a certain amount of bruising is bound to occur.
Unfortunately, some young people expect THEIR “safe spaces” to be modeled on an incubator for preemies, not a boxing ring.