In the OP case, I bet the age of the coworker has a lot to do with it. I felt a lot different at 18 than I do at 48.
Over the last 30 years, I've worn a succession of rings on my wedding band finger. My engagement ring alone, then with the thin gold wedding band. Around 7 yrs married, my dh bought me a double-sided wrap ring with baguettes and small stones on both sides. I wore it until it was too tight (2 kids, weight gain), then purchased an set of 14k gold replacements, set with Diamonique stones. I've also had multiple anniversary style rings set with both real and simulated stones, again with weight change, age, and style preferences. As long as I have something I like and dh likes on that finger, I'm happy. And also happy to say that with weight loss over the last few years, I am wearing my engagement ring and diamond wrap again, with one of the nicer anniversary rings on the opposite hand.
Dh has also had several wedding rings, due to weight gain and me bending one of them into an oval during labor. For our 25th anniversary last year, he let me buy him an upgraded ring in yellow gold and platinum, to show that we made it so far. Whichever of those rings he wears over the rest of his life doesn't much matter to me. I just like that he cares enough to show the world we're married.
And I do know a number of folks who work in jobs where a ring is dangerous. A lot of them have lovely tattoos to symbolize their marriage. I even know a few couples that exchanged 2 sets of rings - one set with lots of diamonds and one plain set, so they could wear what was appropriate to their activities.
The thing is that this is personal. As long as you are happy with it, it doesn't matter what anyone else thinks.