<boring technical stuff>
The vast majority of pedals out there today use 2-layer circuit boards, which means there are copper traces on both the top and bottom of the circuit board. Fora lot of circuits this is perfectly fine, I'm not going to say 2-layer boards are bad. But when you get into any other industry you see mostly multi-layer boards that have internal copper traces in addition to the top and bottom. Starting a couple months ago I've started moving all of the designs of my pedals over to 4-layer circuit boards, which have all audio signals on the top and bottom layers and all power and ground connections on internal copper layers. This is considered "ideal" for noise and stability as it keeps sensitive signals isolated and shielded, and I've been pleased with the results I'm getting from previously troublesome circuits. However, likely the main reason this isn't more common in pedals is that the boards are more expensive. Looking at my circuit boards, the new 4-layer boards are approximately 6x more expensive than the 2-layer version of the same board, so the price bump is an effort to help offset that.
</boring technical stuff>