Transfer data from water damaged iPhone X to new iPhoneX

If it is dead and won’t power on, and you have no existing iCloud nor iTunes backup, then there is no data saved anywhere to transfer to the new device. You cannot restore a backup that does not exists. And you cannot create a backup from a device that is dead.

As is always the case, backups need to be made, and kept up to date, before a device dies. After it dies, you’re just plain out of luck.

You can't without having any sort of backup.