He had great feuds but people view his greatest rival as The Rock who would call Austin his greatest rival.

WWE's inability to build more stars was an issue for sure, and he gets shit for holding guys like RVD and Booker down, but RVD was never good enough to be true top tier and Booker was good but also not top tier in my opinion.

Even Cena in his era of domination had Edge for a while and Orton (as boring as that got)

Imagine Austin with 0 Rock matches and it's a different world. He'd still be at the top tier, but having that rivalry really pushed both of them over the top. all of the GOATs also had a GOAT level rivalry. HHH never did.

When I look back at HHH and that era when he was on TV non stop I can't really think of a memorable rival that really mattered other than HBK well past his prime who was really just being used to elevate HHH.