Nobody needs a smartwatch. The question really is: "Will a smartwatch benefit me?" I can't speak to everyone's use case, but for me it's been really useful for my cycling. I have an LTE smartwatch, so it's nice that I can leave my phone in the car or at home and still track my cycling (with GPS and heart rate monitoring). Less bulk for me to carry around, and I'm protecting my significantly more expensive phone from potential falls or crashes.
This is great for my regular exercise cycling because I don't really need my phone camera or anything with me while doing my regular routes. Just the ability to make and receive a call if I need to and track my cycling performance. And since the watch can also pair with my Bluetooth headphones, I can download a couple podcast episodes and keep myself entertained. Again, all without my more expensive, bulkier phone.
Just like any consumer device, not everybody needs it. You find the right devices that make your routines more convenient.
These little ejector tools are useful for more than just SIM cards. CD/DVD ROM drives have force eject buttons inside tiny little holes that these can reach and push. Many hardware reset buttons are also hidden inside tiny holes.
You could use an unfolded paperclip in a pinch. One of my air purifiers has a reset button inside a hole that is slightly too thin for the paper lips I have on hand. But the SIM ejector tool I keep around fits perfectly.