Nothing you've said here couldn't be applied to an actual Ponzi.
Ponzi schemes can be very convincing.
Much more convincing than the rational you've given.
They are designed to be convincing.
Plain and simple: it's a Ponzi because it's unsustainable and those who got in first make money and those who enter late get their money transferred to the people who got in early. Plenty of people out there called Bitcoin a Ponzi, and they still do.
As it stands now, this entire project is centralized, and the network it sits on is centralized. It's double centralized with multiple attack vectors. Any Bitcoin maximalist would look at these tokenomics and claim this was a Ponzi. Because from Bitcoin's perspective: it totally is. There is no security here. Even the BSC farmers know it: and they still farm BSC. It's risky and you have to trust the dev team: A LOT. Rug-pulls & scams everywhere.
The only reason why things like this can exist is because Bitcoin exists. Bitcoin provides the ultimate security that allows other projects to branch out: getting riskier and more centralized for a potentially bigger risk/reward.
A new scam is launched every day.
No one should wonder why people would call CUB a Ponzi before proving itself.
Go farm some random tokens on BSC and you'll get it.
CUB is a random token to these people.
The fact that we trust CUB is not the standard: it is niche thinking based on trust/branding.