Alot of people get a hard on for 'quality', but as far as I can tell that's entirely missing the point. To make a sporting league enticing to fans, its far far more important that you have parity. With solid enough marketing and effective rivalries, casual fans won't really know or care about overall quality so long as teams are somewhat evenly matched. That's what makes for an attractive product.
As we saw with Super AU, many die-hard rugby people decried "its not as good as the Kiwis!".
But because the majority of games were close, tense, and meaningful, casual fans ended up watching anyway.
Notably, the Top 14 isn't as high quality as Super Rugby Aotearoa either, but it still gets massive fan and media support. Thats because relative skill level is far more important than overall skill level when it comes to making a commercially viable product.
The whole idea of the original Super Rugby was that it offered the 'highest quality' matches. But as we saw, Australians didn't care about how good the Kiwi teams were when Australian sides were getting blown out multiple times a season/every week. As such viewership, fan support and media attention steadily declined in Aus over the two decades of its existance (apart from a few short blips when Australian teams were doing well, which is kinda my whole point).