They're good as long as they don't detect the highest level and rarest items (that are useful). I often find myself having no time or energy to explore "everything" on my own (it's one of the reasons I dropped Tears of the Kingdom. Rewards are typically just not worth it to me) but I would like a middle ground where your manual exploration can be rewarded.
Doing a lot of work only to get a tiny fragment, or an abundant item, or a consumable is a waste of time and makes me angry.
Honestly, collectibles in general are a giant waste of time and I end up having a billion items that I will never use anyway. But I still more often than not explore every nook and cranny because OCD. I'm also a hoarder, thankfully not in real life. My main drive for exploration is probably that I think I'll eventually find things that are actually worth it (99% is not. "You found a consumable that makes this easy game even easier! Rejoice!!" It's like you're working hard to make the game worse, not better, but you still do it anyway in the hope that something good might happen lol.
I guess if the game has a beautiful world and good design, the reward is the journey and imagination as opposed to whatever you're receiving or discovering in the end.
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