The Legend of Zelda: Nuts and Bolts
You are vastly vastly underestimating the amount of work that would take. The only way that would be remotely feasible is if they greatly restricted which items can fuse.
It looks jank and unpolished. I know it'd take work, how much work is up for debate since none of us here are devs on the game and I don't play what if. But considering the fact that it's built of off BoTW (borrowing so many assets) and had damn near 5 years of dev time, it's def a valid criticism.