The final product is different than a mockup from three years ago? Goodness.
This is one area where developers have to be very frustrated with the entitlement of some gamers.
(Developer show cinematic teaser video)
"NO! We want gameplay video! Show us gameplay!"
"But ... but this is still early development, so many things will change ..."
"GAMEPLAY!@! STOP LYING TO US WITH CINEMATIC TEASERS!!"
"Okay, then, if this is what you want ... here is some mockup gameplay we put together using projected settings. The finished project is still years away, though, and any number of things--."
"WOW, THANK YOU!"
"What the hell! This is a downgrade! THE SHADOWS ARE DIFFERENT!!"
Come on, you are being absurd there.
They choose to show it long ago, they choose to show gameplay, and they didn't delivered something on the same level.
If you don't want people getting back on you don't show something that's not going to be true, you are basically lying to your consumers, just like when you go to a McDonalds, see a nice meal in the ad, buy it and it comes like it was flushed down of a toilet, that's not acceptable.
Show the games when they are decently close to release with final builds them, like Fallout 4 just did, that way we know exactly what we are getting and we can base our expectation on something realistic.
I'm ok with cinematic videos announcement as well, as far as they are not "pretend to be", if somebody watch a cinematic they should know it's cinematic and that's it, that's completely fine, choose gameplay when it's ready to show.