What do want him to do? Redownload 100GB worth of mods at some point in the future in which he wants to play the game again?
I don't know about you but I'm keeping my 400GB modded FO4, even if I haven't touched the game in more than half a year. I rather spend 4 hours updating mods than spend 8 hours redownloading everything and spend another 8 hours debugging the crashes.