Social issue dramas like THE DEFENDERS, EAST SIDE/WEST SIDE, SLATTERY'S PEOPLE, and THE BOLD ONES tackled many more tough issues than STAR TREK did, and they did so head-on, without the trappings of purple polka-dotted people, to paraphrase Roddenberry.
If STAR TREK was on par with anything in the '60s, it was on par with other well-regarded action-adventure shows (I SPY, MISSION: IMPOSSIBLE).
Exactly. And I SPY touched on the issue of drug addiction in an excellent episode ("The Loser") guest staring Eartha Kitt where there was no last-minute resolution or rescue. TOS never touched drug addiction and when TNG did it, it was an after-school special.