Moderation on HN is very strict. If Indie Hackers were 'gaming' the system, they'd be banned. That hasn't happened. The posts consistently end up on the front page because people like the site...
Banning on HN doesn't quite work in so off-with-their-heads a way. There are many forms of gaming HN; the spectrum runs from outright evil all the way to accidental. We try to make the punishment fit the crime, so in general a site not being banned doesn't mean they didn't try to game the system.