Recently, someone told me again, "Put some liquidity into AMM and just sit back to earn trading fees."

I instinctively took out my calculator after hearing that...
Honestly, that curve thing is just you helping the market automatically buy low and sell high.
Once the price moves unilaterally, impermanent loss is like a hidden tax slowly deducting, and trading fees might not even cover it.

Last night, I was really curious and tried it out.
A pool I just added liquidity to not long ago, on-chain I saw that swap transaction @0x7b…91c connected three trades, pushing the price in one direction.
My position ratio visibly distorted to the naked eye.
Tried to withdraw but found the gas fee was a lot higher than expected.
Anyway, my mood was a bit wrecked.

Now seeing the "re-staking/shared security/compound yields" set being criticized and mocked, I can understand:
The yields look like they stack layer upon layer, but so do the risks and friction costs.
In the end, it might just be us small retail investors paying tuition...
For now, market making really isn’t just lying around earning money.