Depth, not volume, decides what your order costs. A pair reporting $50m of daily volume but holding only $80,000 within 1% of mid will move several percent on a $200,000 order, and the difference between those two numbers is where fake-volume hides.
Depth is also conditional. Market makers widen and pull during news, so the book you measured in calm conditions is not the book you will trade against during a liquidation cascade. Depth charts show a moment, not a commitment.
Compare it against your intended size before entering, and remember the exit is the harder half: positions are usually built into strength and unwound into weakness, when depth is thinnest. On-chain the equivalent measure is pool reserves and the resulting price-impact.
Related: price-impact, fake-volume, liquidity, maker-taker-fees