Most certifying agencies for recreational scuba place an arbitrary cap of 130 feet. It’s not law, it’s just a suggested maximum depth for using recreational scuba gear that MOST people will be ok with going to that depth and returning to the surface with no decompression obligations given that their bottom time doesn’t exceed NDL ( no decompression limits). It’s also about the depth before most (not all) divers begin to experience nitrogen narcosis. It’s actually possible to go much deeper on regular air with proper equipment and training. Your only limits in open circuit scuba are your training,experience, equipment, oxygen and nitrogen exposure and the volume/ type of gas supply. I’ve known divers, using normal 21% O2 air, to dive to 250 feet even though theoretically, they will have exceeded their PPO2 exposure( again, another number pulled out of a hat because it’s an average for most divers that still includes a safety margin).
Technical scuba divers go much deeper. They’re still using open circuit scuba gear but are using multiple exotic gas blends and some specialized equipment and training. The record set here is over 1,000 feet. My personal best is 353 feet on trimix with two back gas mixes, a deco of 50% and a crap load of paper scissors rock and hangman on a slate. ( deco games) I could have made the dive a lot cheaper but I hate hanging on a line.