Uniswap (v2) has simple contracts, has been audited multiple times, holds billions of USD and it has not faced any kind of systemic attack. The only issue that I can think of is that pools with low liquidity can suffer from front-running.

Even the fees are not a "problem", if you consider that there are already roll ups (loopring, zkswap) that run pretty much the same version of those contracts and cost fractions of a penny.

Curious to hear more about this as well. How is Uniswap?

Uniswap, pancakeswap, 1inch, apeswap, sushiswap, traderjoes, Crono, quickswap, paraswap and those are just off the top of my head.

All of these projects have hundreds of million to billions in tvl and have been running fine for years.

Dexes are the backbone of the defi community and share very little in common with centralized exchanges.