I think they help, but they also change players' view when they land on your base and must decide decide to attack or skip.
- Players that find your base with a ground army are much more likely to pass your base.
- Players that have an army comp that is designed around circumventing walls are not so intimidated by your walls, and so are more likely to attack you.
What would be nice for you is to find a player in the same shoes as you (similar base layout, same defense building upgrades, similar trophy count) but has weak walls. Ask that player for their experience.
I bet you anything that player has been attacked by much weaker armies AND has experienced being 3-starred more than you.

