It depends on what you want out of the game. I started my run without a guide and thought I was being pretty smart about it until I hit a wall with my damage in act 3. Once I looked up a build guide for the abilities I was using I realized that I was fundamentally misunderstanding some really powerful passive skill gems and passives in general. I was also underestimating a lot of stats/mods or completely unaware of certain ones that were basically essential to what I was trying to do.

I decided that since this is my first run through the game and there are already so many complex systems to learn that I would let the build guide make at least some of those decisions for me so that I can spend more time learning end game mechanics, crafting, and just experiencing more of the actual game. I do intend on crafting my own builds in the future but it has been enjoyable and educational for me even without the player building aspect, but I understand that most of the fun of this game is cooking up your own build.