It was incredibly easy to get upload credit for seeding freeleech torrents (which included 10-20 albums of staff picks once a month or so) or re-encoding releases that were missing v2 or 320 encodings and scripts would pick up the releases. You could also just watch for new releases or follow trends and you'd easily get 5-10x ratio seeds. Also, you can get a $5/m seedbox to keep your downloads alive and you'd easy get back to 1.0 ratio assuming it wasn't some truly unlistenable album. I had a ratio of like 15 or something on what by leaving my computer on. At no point was it impossible or even difficult to get upload credit on any of these websites unless you were just leeching/turning off uploads. I just pulled up a larger site and I have 15 TB up, 1.15 TB down, and I'm doing absolutely nothing besides downloading stuff and deleting the torrents once I need space.

Newer torrent sites try to solve this with rewards for long-term seeding, which also helps keep the site alive but isn't zero-sum like the ratio.

Yes I remember even at the time people were laughing about the hilarious requirement for everyone to have a seed ratio greater than 1. Those sites were basically unusable for people who came to them later.