Nobody is saying that LOTR didn't use CGI, people are just pointing out that previous trilogy wasn't equally dependent on it. Back in 2001 Jackson used to shoot as much as he could on location. Location, location, location. Now it's mostly green screen to the point that even McKellen complained about it.
There was a palpable, grounded feeling to LOTR, feeling that it's a real place that You could visit. Now "The Hobbit" is gorgeous and I've said plenty of times before that the colorful look fits the story. But it doesn't look as real as LOTR tough. Most of locations in DOS have that CGI patina to them. Even places that could have been shot on location or easily faked in the studio with an elaborate sets are now clearly CGI. A decade ago they used biggatures. They didn't this time around. The opening vista shots of Lake Town in DOS are very pretty and atmospheric, but they are clearly CGI. Back in 2000's it would have been a no brainer for artisans at Weta to create model biggatures for this place to be shot from above (after all, what is Lake Town compared to Minas Tirith for example, which was also built as a biggature). How more realistic it would have looked? How more impressive would those opening shots be? You want to see the difference between the visuals in LOTR and Hobbit? Compare Lake Town opening shots, with the shots of Edoras when Eowyn is storming out of the Golden Hall, and Aragorn, Gimli, Legolas and Gandalf arrive in TTT. Thats the difference.
Some goes for most other places in DoS. Thranduil's halls were very pretty, but I could easily tell that besides the king's throne and the immediate floor area around it it, nothing else in that "set" was physical. In FOTR at least they digitaly composed Lothlorien out of variety of real elements.
And that whole color-enchanced, fairy tale look of the "Hobbit" could still be easily achieved on the physical sets by simply color grading the shots (like they did 12 years ago, but more). It would be just as beautiful, but it would look more real, more palpable.
Then there's the matter of CGI orcs (which I actually like).
All in all, I am not saying that Hobbit looks bad. Far from it. But it certainly suffers in some aspects becouse of PJ desire to bring it all in 3D and HFR (many of the CGI changes were made becouse of those formats). And I think it's silly and not fair to lump together all the arguments of those who complain about the overabundance of CGI and say that "LOTR used it too".