I played Minecraft a lot, about 1500h+, Fortnite about 400h. If u want to chill sometimes I recommend Minecraft a lot. On the one side you can play multiplayer to play like on pvp servers, on the other you can create your own world a chill in it (with a friend for example).
Fortnite has more action (there is building mode but still, you can not compare Fortnite with Minecraft).