Coinbase's largely unregulated business model of collecting inflated trading fees may be in trouble, as competition for crypto trading capital heats up.A feeding frenzy of low fees/commissions for crypto trading is beginning, with new offerings from established Wall Street brokerage houses.COIN's IPO at the peak of crypto pricing in the spring of 2021 may be akin to the ill-fated public deals of the Dotcom era in 1999-2000.