Most likely: you (or your wallet) choose that fee. Just like in Bitcoin, there's no upper limit in the fee you can pay, and considering you're sending a small amount, the required fee can be higher if the network is congested.
I was thinking it could be because of the transaction weight before but by tracking the txid, you are very right, adamcro definitely customized the fee.
Or maybe he is using a non-reputable testnet wallet, but I doubt that because the fee using testnet is very low.
I wish I customized the fee. I guess Tatum.io customized, because I'm using their API