That's correct. Iirc, dpkg and apt were ported/compiled for iOS and then cydia was created by saurik which is basically just a frontend for apt. Unlike on e.g.

That's correct. Iirc, dpkg and apt were ported/compiled for iOS and then cydia was created by saurik which is basically just a frontend for apt. Unlike on e.g. Debian, paid repositories became a thing and some of those became first class citizens of cydia, or in other words, they were pre configured in cydia. A lot of the business in jailbreaking always had to do with pirating and cracking apps and there were alternative app-stores offering paid apps for free. This practice was apparently more common in asian countries like china which led to some jailbreaks being supplied by chinese groups funded by alternative app store companies. However do note that this was never embraced by cydia, third party repositories and stores were used for that. Cydia and jailbreaking is how I got into computer science and learned how to host my own debian repository as a kid before I got into actual debian and linux. I don't know how the jailbreak community is doing now and I have moved to android a long time ago, but I am eagerly awaiting the time when apple has to allow side loading, then I might become interested in iOS again.