The recognition in Season 2 when Harringrove meets, is that Billy's main coping skills are internalized, self-destructive, and numbing because he doesn't really have any good place to put his emotions.
music so loud that he can't think straight
driving fast and erratically
(most likely) working out until he drops
doing everything he can to avoid being alone with himself and his thoughts.
and that Steve's coping skills are more externalized, which he probably sees therefore as being helpful or positive behaviors rather than avoidant ones.
fighting/killing monsters
putting himself in dangerous situations
sacrificing himself for others
dating for the sake of dating
needing to be in the company of others often
trying all he can to avoid being alone at all because he can't tolerate it.
Steve fears being unwanted while Billy already feels unwanted. Billy actively destroys things that fall contrary to what is his reality. Steve tries to busy himself in all ways possible to protect himself against the threat of being called useless.
Billy has been told his whole life he's unlovable, and Steve's life comes into crisis when Nancy admits that she doesn't love him.
They meet at a time when they're both wounded and angry. Billy who's used to the hurt, and Steve who feels insecure and vulnerable.