system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why divers coming out of depths need to decompress to avoid decompression sickness, but people who fly on commercial planes don't have an issue reaching a sudden altitude of 8000ft?

I've always been curious because in both cases, you go from an environment with more pressure to an environment with less pressure.

Edit: Thank you to the people who took the time to simplify this and answer my question because you not only explained it well but taught me a lot! I know aircrafts are pressurized, hence why I said 8000 ft and not 30,0000. I also know water is heavier. What I didn't know is that the pressure affects how oxygen and gasses are absorbed, so I thought any quick ascend from bigger pressure to lower can cause this, no matter how small. I didn't know exactly how many times water has more pressure than air. And to the people who called me stupid, idiot a moron, thanks I guess? You have fun.

Edit 2: people feel the need to DM me insults and death threats so we know everyone is really socially adjusted on here.
gpt
Going from sea level to 8000 ft is a pressure difference of less than one atmosphere. Every ~32 ft of water depth is equivalent to one atmosphere. Divers undergo a much greater pressure differential than personnel flying in aircraft.