It could be fixed that way, however I only want the taskbar on the right monitor.
Suppose I'll just have to accept that there's no reasonable solution to my problem and just keep moving the game window over.
Now I can understand older games opening on the main monitor only given multiple displays weren't often used then, however games like Fortnite I'd expect to be able to select the monitor given multiple monitors is pretty much the norm now and not everyone sets the main monitor as the middle one.