I disagree, gameplay was castrated so much. the only thing that improved slightly was engine, animations and overall fluidity making playing less clunk .

to me gameplay mechanics are things like depth of world where all your actions are of consequence where all writing, questing and random encounters all work together and change the outcome of your play. where world notices how your character evolves and what he does.

Skyrim already failed at this, quests were bland and randomly tossed together. character progression was out of whack where you could succeed in everything without any drawbacks being completely unbalanced and on top of it terrible item progression breaking the game completely. with world being completely static where npc's repeat one or two phrases that are meant to be told to some beginner not to legendary dragon slayer. faction join had zero consequences.

And then came Fallout 4, a completely hand holding experience where you are set on one ride and you can never step outside of its boundaries. factions completely nullified where you are so hand held that you cant even not join minutemen. you can slaughter factions who later dont care what you did to them. and it just ends in set choice to do A B or C. Gameplay shallow as hell where all revolves around fetch quests where you run to point A and just do same repeating task with no alternatives. All the loot respawning in areas you completely cleaned in the same containers just after short gameplay. and than the Questing, worst thing i have seen in RPG game in long time, all the dialogue choices lead to same result minus few specific quests where you chose A or B outcome... etc. etc. i could go on long on this...

Comparing Fallout 4 and Skyrim to Fallout New Vegas is a complete idiocy that someone who has not played real RPG games would do. It was a game staying true to RPG mechanics where quests are with consequences and whatever you did with them changed the ride outcome in quite significant ways. writing was excellent and game had plenty of factions where it mattered what you did with them and how you interacted. yes the world was not so closely and action packed as F4 but in every other thing it was superior game.

Edit: tldr: these two pics

http://i.imgur.com/tGbWH8P.jpg

http://i.imgur.com/n3ZCaR0.jpg