Hello Ali Mac,
Welcome to Microsoft Q&A forum.
I understand how frustrating this is, especially with such a large download. Unfortunately, a game doesn't operate using the executables files and the executable folder alone. It also places many operation and configuration files on the system folders and hidden folders for the communication between the game and the system. So, copying the game folder alone won't help since it won't be enough for the game to operate.
Sea of thieves is a game that is available in the Microsoft Store, if you already own the game, you can simply log in with your Microsoft account on another computer and download it directly to that computer. Your progress is saved in the cloud, so you can just sync it to retain the progress. Thank you for your understanding.