No, ED didn't make sub-optimal slotting strategies more viable, it just made the most efficient slotting strategy unviable.
I'll repeat it another way, ED did not make any slotting strategy more effective than it had been Pre ED, it just made the best strategy Pre ED slotting strategy ineffective/unworthwhile.
There was only more slotting variety because the best strategy became worthless, net effectiveness plummeted. We can engage in infinite sophistry to make it sound like ED made 1 acc, 3dmg, 1 end reduc, 1 rech worthwhile but the truth remains that you don't need the greater recharge if you have greater dmg and they are not equal, because of ED you now need the end reduc because you have to use your powers more to get the same result as Pre ED again an unequal trade.
Let's pretend for a minute you have a point. Ok, so what? What does it matter? This is an argument that was lost and dismissed over ten years ago at this point. It didn't stop the change from happening, the game never got rid of ED, and there is nothing to suggest it will happen now. It's over and you lost, it's that simple.