The sweeping motion of a mechanical watch is somewhat incidental. Yes, higher-end watch movements will beat at a higher rate than cheap ones, thus making their motion more smooth and their timekeeping more accurate. However, after a certain price point (let's say, >1k USD) that ceases to be a factor and choices like material, brand, complications (aka "features"), and finish make up most of the expense. Beyond that (>100k USD), you get to the price point of watches as high end art.
Anyway, for me as a tech guy, it's about style and simplicity. I want a beautiful, legible dial in a form factor that doesn't make my wrist look like a toothpick. I have a compulsion to always know the time, while also wanting to disconnect from my phone for certain things. A smart watch is too phone-like for me.