Ethereum has the first ever decentralized banking system based on on-chain smart contracts. I'm earning high interest on usd stablecoins for several months now. The interest rate was double digit until very recently, but even 5% is still very good for a completely anonymous system.
DAI itself is a decentralized usd stablecoin, meaning it can't be confiscated by the issuer. It's overcollateralized by locked eth. Anyone can generate new dai after locking eth. Those two together make the previously impossible possible - an Iranian or Venezuelan citizen earning interest on a USD-denominated savings. This is all called DeFi. Once mortgages and other external assets are tokenized, it's going to allow fully decentralized mortgages.
https://trade.dydx.exchange/markets
https://app.compound.finance/
>Bitcoin solves a real problem: it allows people to escape and bypass existing financial system and continue doing business, save and not be subject to policies outside of their control. It is black market money which governments hate and will try to outlaw in some way.
Bitcoin completely failed, as majority of its hashpower is located in China. The Chinese government can tell miners to censor transactions tomorrow and to orphan blocks from non-compliant miners and it would happen. There's no defense against this. Changing PoW via a hard fork would result in a gpu-secured network that's even more vulnerable than an asic-based one, as it's easier to a large entity to rent or buy enough gpus.
PoS is the only defense against such centralization. Most hashpower is going to be an impossible to hide industrial facilities, while PoS only needs an internet connection, much harder to catch. More importantly, even if a determined attacker acquires a very big fraction of the tokens and attacks the network, a hard fork can just delete the hostile accounts. One a gpu based PoW network is attacked there's no solution, as it's not possible to make the attacker's mining hardware ineffective via a hard fork.