Yoshi's Island, world 4-1, there's a Shy Guy pipe with a small divet to the left. If you take a koopa shell, stand on the edge of the divet, and spit it, it'll bounce off the pipe and onto Yoshi's feet. Instead of damaging Yoshi, since you're technically above the shell by standing on the edge, it simply bounces back to the pipe. Any Shy Guys that hop out while you're doing this get shelled instantly, and after the 7th, you get a 1-up. Each one that's hit after this grants another 1-up, meaning you can effectively have infinite lives.
I don't know how I figured this out when I was 6-7, but I did. It helped me a lot through world 5 having over 500 lives, given I was terrible at platforming on ice, and those levels felt punishingly difficult.
Why fix it? It lent itself so well to the open-ended nature of the game. You explored enough to find resources to make stamina-boosting items, and so you should be rewarded in the same way one might secure a bunch of stamina upgrades or find the climber's outfit. That freedom to experiment is part of why BotW is so great in my eyes.