Atomic swaps are being used by many DEX's and dapps to trade bitcoin and ETH like coins with each other --it's not impossible.
Sure it's possible, but I don't know of a usable enough service for atomic swap.
I found only AtomicDEX, but they don't good enougth, they allow use for trade only their own wallet.
U say many, so give me links where i can swap BTC to ETH by atomic swap.
Use these platforms at your own risk. They can be dangerous and are always potential targets of hacker groups. All these platforms use atomic swap features.