Step 3: Stopping the Rate Limits
Most websites do not like having their servers pounded by legions of robots.
Because we are the robots for once, this is a bit of a problem. Thankfully this requires one minimal input in addition to your existing configuration, which goes as such:
--sleep 10-25
Websites know that bots are hitting them, but they will tolerate that activity as long as it is not too aggressive. And by default, as you may have seen in your test run, gallery-dl is quite aggressive. So it is not enough to just work with the normal settings. You will want to download larger galleries at better qualities, and you will eventually hit this one way or another.
Rate-limiting is essentially how a website protects itself from bad actors, excessive bandwidth use and potential downtime. Every time your browser asks for something, whether that is an image, a page, or anything else, that counts as a request. If you send too many, whether you are a human or a robot, the site will start pushing back.