0.03% is a ludicrously small amount to make for losing to arbitrageurs. It may work with lots of sideways action but crypto tends to go in one direction for a long time so most LP's lose.
For that matter, though, a lot of people who buy the top lose.
Crypto needs to have more UTILITY. The financial sector in general is just overleveraging the normal economy, this isn't just crypto. Ironically, Bitcoin was started in response to the 2008 financial crisis, where the govt repealed Glass-Steagall and then bailed out the banks. At least here, the government isn't bailing anyone out with taxpayer dollars.
And look... in China it's not much better. Their real estate bubble is very reminiscent of 2006 USA ... Evergrande is just the most well known poster boy.
Said differently: The financial system has trended toward centralization over the past 5+ centuries, because there are obvious advantages to it.
One could argue that there are plenty of downsides to over-centralization (i.e. 'Too big to fail'), but the solution is not to start from scratch, it's to logically think about the kind of financial system we want (given the one we already have) and build that.
Conversely, the answer is not be techno-cowboys who know people with cryptography degrees who re-discover what bank runs are.
The ones that haven't (yet) been hacked, anyway...
Besides, which ones really are decentralized? Can you name one that doesn't have a central control point? Most have an update system, allowing one person to either completely modify the smart contract code or to enable/disable trading.
AFAIK Uniswap doesn't have an upgradeability proxy, they just deploy new versions and the old ones stay up. That's only true if you aren't using a L2 though, all the current L2 implementations are upgradable.
Looks like you're right - Uniswap v1 is still usable, they had 'proxy' contracts that could redirect users to more recent versions, but you can, if you choose, interact directly with the original version - it wasn't turned off. However, since the liquidity all moved into the later versions, there's only about 1/1000th of the trading left in the original. (and you get to keep/be exploited by all the unpatched bugs, yay!)