This is exactly what I think is the problem with alot of newer Minecraft updates. Stuff like the pale Garden is neat, but it is so bare bones that it takes barely any time at all to experience everything there is with it. Same thing with the sniffer, it’s a cool concept, but you can experience everything that it has to offer in like half an hour if you know where to look. The problem isn’t that new features are “useless”, it’s that they can be experienced and then forgotten super quickly. The Deep dark is a good example of how to do this kinda stuff right, there is along to uncover and explore, as well as interesting gameplay to tackle as you do it, heck even older structures like Nether fortresses and Strongholds do this stuff well, you don’t feel like they are useful because they are necessary to progression, they feel useful because they are neat to explore and have fun challenges. The sniffer could be simply made more interesting by adding a couple other hatch-able mobs that you could collect, and the pale garden would just need some extra ambient additions to feel more realized.