Sorry old bean but you are so wrong it's astonishing.

Blade Runner is all about the characters, the plot, the plausibility (if you can get passed the dodgy date setting) and tangible atmosphere.

If it had been made by the BBC in 1971 it would still be a classic without the special effects and the design.

Sure, Deck being a skinjob is only a barely hinted at bit of whimsy in the theatrical cut, so what?

It's still a film about identity and humanity.

Pris and Batty are still genius children with sexuality inside superhuman adult bodies (that comes from the performances not any special effects).

The speech Tyrell gives Batty about why he can't extend his lifespan is poor grounded science.

Prometheus is about nothing, the characters are implausible and the science is awful.

At times it does look nice though and that's all it has going for it.