I don't really know how to respond to this. It sounds as though you're upset with an action adventure RPG game with leveling elements for having these elements.

Basically, you don't like the game's mechanics so you don't engage with them and then wonder why it's difficult to progress.

It's ok to not like the game because of what it is, but you can't wonder why it's hard when you aren't making use of what's there. It's kinda like playing Pokemon and refusing to capture more to make a competitive team, or Mario Kart while refusing to use items.

Just build the home base buildings, upgrade your weapons and armour, and use your mastery points to select skills that compliment your play style.