Energy weapons are definitely inefficient, there's no way to argue that point, the numbers are just worse. Almost none of them have better than 1x efficiency, and most are significantly worse than that. That means you're converting your dissipation into damage less efficiently. When I compare ships, I add ~30-50% to their dissipation in my head if they have access to ballistics.
For comparison, a heavy mortar + heavy needler do 610 dps to shields for 380 flux/sec (at 22 OP) vs two pulse lasers at 606 dps for 666 flux/sec (20 OP). Armor penetration cant be determined as exactly because it changes depending on the current armor value, but at 500 armor (very normal destroyer number), the two pulse lasers are doing something like ~100 dps (.166 damage multiplier with 606 dps) and the one heavy mortar is doing like ~134.5 dps (.3 damage mult with 440 dps vs armor) + 18.75 from needler (minimum mult of .15 and 125 dps vs armor) so the dps is better for the ballistics and the efficiency is also better for ballistics. Vs. hull, pulse lasers again have the dps advantage (606 dps for 666 fluc/sec) but the ballistics are still more efficient (470 dps for 380 flux/sec).
You just get much better performance for similar OP with ballistics particularly medium and small ballistics. High tech ships have access to inferior weapons to balance their superior stats, systems and mobility. My experience with AI high tech ships is that they wander off chasing a frigate and get killed by fighters or reinforcements.