I'll cede the obvious point that there are less female participants. Two counterpoints, because I'm interested in your thoughts:
First: Wrestling is a novel sport. Women's wrestling shouldn't count in any way as a "first generation" sport because of how the athletes were grafted into and competing within an already established system against opponents (boys) in that system and with the established coaches and in the same households of that system. Any girl 25 or younger has been groomed to the same level as her male counterpart for her entire journey, with no missing piece of training, knowledge, or competition level. It's no different from African & Asian track and field athletes from non-traditional nations now winning medals in things like javelin and sprints that they never won before. Those athletes are being sent to academies and training programs in the US and Europe at a young age, where they're grafted into a long-established system. Women's wrestling is completely different from emerging women's soccer opportunities globally, for example, where the generations of time needed to establish competition levels and training frameworks is much higher.
Secondly: Even if we had only 30% of the current number of boys participating in wrestling in the US; if we had the same coaches, the same number of competition opportunities, the same number of university slots available, and the same level of fan support--the slight reduction in overall athleticism would be almost completely offset by the training and experience built up by those 70% of different athletes who got to inhabit the high-end opportunities from a young age. The level we'd see at NCAAs would see only a mild drop-off.
Again, I'd say this: even though Helen Maroulis started out at a time that the girls around her wouldn't have had this fully developed system across the full depth of nations, the fact that she keeps winning now against the generation who DID have it from the time they were 6 or 8 years old onward validates all that she's accomplished and should put her in a general discussion as one of our 3 or 4 best wrestlers ever.