Nuzlockes are not an ideal way of making the game harder.
Before I explain, if you like nuzlockes, that's cool I hope you have fun and continue to have fun.
But I don't think adding permadeath is a good way of making the game harder. As someone who really enjoys competitive (6v6 singles), I think it shows off pokemon's battling system at it's best. And things that are key to battles are the ability to sacrifice pokemon strategically either to get a 'free' switch or to take out a dangerous pokemon with explosion. But with permadeath those strategies are taken out and it encourages more safe and quite frankly more boring strategies like over leveling and looking up what pokemon trainers have before you battle them, which I know people now limit their level and play with randomizers do prevent that but in my mind that just makes it worse. In that case the game becomes extremely random whether you win in any given situation, which can be fun but I don't think it's the ideal way to create a pokemon experience with a satisfying difficulty level. The times where I have had the most fun playing pokemon is when I am battling the champion because usually the champion is the only time I feel like I am having a true battle of equals, where both of us are doing everything in are power to win the battle by any means necessary but if you introduce permadeath it's no longer a battle of equals.

A