Fallout 3 was one of my favorite games at the time. Fast forward to Fallout 4 and I enjoyed it in my first play through, but the gameplay was really mediocre considering it is 2016. I don't care about graphics, but the performance in the game was choppy as hell. Also, they give you the illusion of freedom, but really offer a pretty linear experience.
I recently got into the Witcher 3 and man, this game is great. While the story is on rails and offers less customization, the execution was so much better I didn't care. I was scared to get it because I hated Dragon Age Inquisition and heard it was similar, but everything I do in the Witcher feels like it has purpose. The graphics are amazing, gameplay is good, and story is one of the best on a console Ive played in years. Feels like I'm playing in a Game of Thrones type setting.
So yes, for many Fallout 4 was a pretty big disappointment for fans of rpgs. If you are new to Fallout you may still love it and I'm sure the PC version is a better experience.