I started using SRT for rec-climbs in the early 80s. Despite the fact, in my everyday work back then, I stuck with using DRT. Ah,,, the agony of body-thrusting, and fighting to cinch a seized taughtline hitch up a sticky pitched-up rope. Jolting pains through my neck and upper torso. Yeah, I remember thinking to myself back then, I'm a real treeman now! The creed of the old climber in those days was unspoken, but as a young'un learning the ropes I heard it said more than once, "Just bear the pain, and get'er done."
By the latter 1990s I was well into using the new friction hitches, and their minding pulleys for self-tending the line, which was a huge improvement over my old school DRT! In 2002 I jury-rigged a rope-walker into this much improved double line system. If you recall the Double-Line Rope-Walker. It incorporated the climbers legs into the vertical effort, and by it much improving climbing posture, and relieving a lot of the pain. Still, as DRT goes, it was only half as efficient as SRT. Had I continued climbing through today no doubt I would've made the full transition into SRT for work climbs. But my accident in 07 changed all that.
Since the internet the innovations in climbing gear and technique keeps coming faster, and what I've seen to date trumps all the combined improvements achieved in this industry through the 50 years before it. I can't help but wonder though, how many more significant improvements can really be made before it just comes to re-inventing the wheel? A quantum leap, perhaps, maybe the answer!