I am confused, is this the best BTC/ETH DEX for swaps?

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Hey guys just came across new feature on perpmate dex, they added swap I just tried to test what rate I get for USDC worth of $83,000 into BTC and it actually gives $82,993.18 is the fee just $7? Usually when I do uniswap or other onchain dex I get less for each swap (fees,rates, price impact), I assume that they have more liquidity of BTC but less in USDC? so they give better rate, can someone explain?

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