Being a liquidity provider in an AMM pool is the same thing as actively trading.
Except instead of making conscious decisions the algorithm does it automatically.
Very similar to running a bot on non-AMM orderbooks.
Every trade requires two parties.
In an orderbook the liquidity providers are makers only (limit orders).
In a basic AMM, liquidity providers don't get to pick and choose their limits,
so they are kinda like makers and takers on a sliding scale.
Meanwhile, slippage is only relevant on an orderbook when bots don't replace that liquidity behind you and you'd have to sell at a loss. Unsurprisingly, slippage happens when the price slips. The only time price doesn't slip is a static limit order. Everything else is slippage.
I did like a dozen hours of research on this because it was explained so poorly.
Link a better explanation or come up with a relevant example with numbers if you think you can prove otherwise.
I'm guessing you did not read the relevant post I wrote that I linked in the previous comment.