There is no misconception. It’s called “not paying attention.” Or more likely, “bitching about TFA while praising the OT for something that either applies equally to both or is actually worse in the latter.”

I love the OT and they did as much as they could with practical effects for the time, and they’re impressive for the time, but they’re still obviously practical effects that you can see the seams on. Saying that the OT’s practical effects were light years better than TFA’s is ridiculous. Perhaps more impressive given the limitations of the times, but not better.