Use https://jup.ag/swap/ which is a DEX aggregator. I think phantom is more expensive than on Raydium but not positive

Phantom charges 0.85% on some pairs, eg SOL to USDC, so that’s the extra cost. it still routes through jup though.
So, as it’s a great wallet, and they need revenue to be more epic, maybe smaller swaps use them, and larger swaps, use jup.ag directly.

I second the suggestion to use Jupiter, but I still use radium occasionally. Can’t remember the last time I used a wallet to swap. I also don’t remember ever getting a higher dollar value worth of what I swapped to, but that happens occasionally in Jupiter

In wallet swap in phantom can lead to a loss of a percent or so more than simply swapping on jup. It’s reflected in the price impact percentage. There may be loss elsewhere, but that’s one place I’ve noticed it occurring.