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.