You misunderstand. The very reason that this Binance hack is a huge issue is that $5B was concentrated in specific wallets under specific keys.

A decentralized network of wallets and balances doesn’t present an attractive target for hackers specifically because the payoff per wallet is so small!

It is exactly the centralization you are defending, which is at the root of the problem. In the decentralized case, no one has to determine who is a student or a teacher. If a teacher needs to pass KYC with a marketplace, they do it once, and from then on can permissionlessly receive their small payouts.