I needed to keep track of the time and I don't always have my phone on me so I got a mechanical watch instead. It's great! No having to charge it, no chance of it tracking me and I got a new hobby/interest out of it.
I love my smart watch for checking a notification that I can't pull my phone out to check as my hands are usually wet and gross from my profession so it only makes sense to me.
Also, they work great as fitness trackers these days too, if you're into that kind of thing otherwise a mechanical watch will work perfectly fine.