And it's overpriced.
If you think Bitcoin price now is overpriced, actually it's not.
People can purchase Bitcoin via off-chain, so technically they don't have to pay fees to miners to own Bitcoin, which mean they bought lower than what it should be. Since you're wishing Bitcoin to be used as a currency and not linking to centralized exchange, Bitcoin price would be higher than now.
That's not true. In a pyramidal scheme, the profits of old users are directly generated by the incoming money of new investors. it doesn't necessary mean new investors lose; it means that after some point, the whole thing will collapse, and then they will.
Any kind of investments works like that.