I would say the inverse. The only people I know that leave a "watch" on are sleep trackers.

Which is a tiny tiny niche

Really? That's surprising. Back when I wore a watch (over ten years ago), I only took it off for showers. Part of the appeal was being able to leave it on at all times and not have 'yet another device that needs special instructions before sleep'.

Yup, even the people who are "watch people" (ie - they think nothing of collecting expensive swiss hand-made ones) are the same.

shrug

You're ignoring that there are other watches besides smart watches.

My old non-smart watch had battery that lasted 2 years, and generally I never took it of for sleeping.

Nope, I'm including that. It's anecdotal obviously but I've only known one person - ever - who did that with a regular watch.

Was kind of gross tbh.

That's another strong point of Pebble, I can wash it :)

I think people of a certain age might prefer taking their watches off when they go to sleep because that's how it was supposed to be. Some watches are also heavy.. You can damage the watch if you wear it at night or accidentally wake your significant other.

How exactly does one damage a watch while wearing it in bed? Also not sure how wearing a Pebble would wake a spouse/SO. A heavy gold watch might, but Pebbles are very light and low-profile. And the fact that the alarm vibrates to wake you instead of beeping means you'll not wake anyone else up when your alarm goes off.

Exactly.

I have a Pebble. My SO also has a Pebble. We can sleep together just fine, without taking them off.