I think I found a counterexample to the common wisdom that more walls always create a stronger part.
The pictured S shape is 1.5mm thick, so printing with 2 walls leaves no room for infill. My testing wasn’t very rigorous, but it seems that the hybrid structure of walls + rectilinear infill is 10-20% more rigid than walls alone. The infill adds strength by cris-crossing between adjacent layers.
I think it’s fine to include a concentric top/bottom layer, but multiple identical layers weaken the part. I also tried 0 walls (infill only) and that was garbage.
All you’ve done here is create more walls using a single piece. If you want durability, your design will win as it allows for flex. If you want rigidity, it will be less rigid and take longer to make due to its complexity.
The loss in rigidity is due to creating weak points as the line turns. The gain in flexibility is exactly the same weakness but now a positive. It will take greater force from weight, butt less impact force.
If you’re after rigidity, either cram the space with as few complexities as possible, or fill space with triangles.