I think it’s (unfortunately) more a case of Hive Fest attracting active people with resources and loyalty rather than actually generating them. It’s a bit like saying that campaign rallies generate more politicians than online discussions just because when you count the attendees, politicians are much more represented there than in your Facebook feed. Or in random Joe's FB feed at least, I don't know how yours looks like :)

Attending HF requires resources. This year’s Barcelona for two (flying with a European low-cost carrier and staying in budget-friendly place; not a hostel, though) would probably set you back about €2,000. Including HF tickets for two.

If you have those resources (and are willing to spend them on a trip like this), it’s likely that:

• You’re already a loyal user. Otherwise, you’d just take that money and go on a much more interesting or longer vacation of your choicec.
• You have the means to run a witness server. It’s an investment. And I’m guessing that at today’s prices, it’s a losing game for anyone outside the top 20. Attending HF then becomes a way to gain political points to help you break into that top 20.
• You have enough RC to create alt accounts. And maybe the wil to play around with them. For example, I created @actifit-godfish and more recently @dead-pets. But realistically, I haven’t onboarded any actual new users with these two accounts. And those I did actually bring in signed up through something like Ecency, so they wouldn't even show up in this kind of metric anyway.
• And finally: you have enough resources so that you don't depend on Hive for extra income. You don’t have to spend hours here every day grinding out posts and comments for a few dollars, so you’re not at such a high risk of burnout. A price drop doesn't become an existential threat to you. You can chill and be active once in a while. For years.