It's ideas are great and a technical step up... in theory, but they just don't work all that well in actual gameplay. I think a lot of that comes down to it's aging engine that is struggling more and more to keep up with current gaming technology. So good ideas like a new speech system with fully voiced player character, more loot, a new settlement management aspect, improved mechanics for things like Power Armour and a full crafting system just don't work as well as you might think. In fact they are often so often distractioing that you barely even focus on the main story at all..
You spend WAY more time doing tedious busy work like gathering crafting supplies and maintaining your weapoms and armour, the new dialogue system actually gives you less choices and the building system is a nightmare that makes it almost impossible to get things lined up exactly how you want them. Good intentions but just not as good in terms of execution.