>>17432601There are lots of legends in wrestling. Gimmicky ones and non-gimmicky ones. Taker had the fortune to have his legend status marketed aggressively while he was still a massively popular full-time WWE star and he never fucked it up for himself (showed up to work sober). Another important part was that he was consistently present in the WWE system for 30 years and had a level of control over the narrative of his act's legacy that most other HOF level WWE/WCW/etc stars don't.
I would say his legacy as we now know it was shaped by a smart marketing push WWE started in the 2000s to keep their most iconic remaining post-Austin/Rock wrestler from getting too stale and possibly to refresh him when he returned as the Deadman after years of being a biker chud. Keep in mind the Streak was first acknowledged in 2002. Taker was absolutely invaluable to WWE by 2004 when they started leaning more into the Streak. Also DVD documentaries.