I definitely think FO4 has much better gameplay than 3. I replayed Vegas a while back and while it’s an awesome game in so many ways, the gameplay feels archaic compared to 4. You can improve that some with mods but it’s never going to feel as good as the native solution.
4 has weak writing, there’s no doubt, but it improved on 3 in many ways I think. There are really only a couple areas where I think it regressed. Most others it far surpassed.