I am in a restaurant now, a midsize place doing brunch, and my Apple Watch is recording 80 decibels. It would be louder if I were at a table but I’m off to the side at the bar.

I enjoyed this article, albeit it’s from 2012: “Working or Playing Indoors, New Yorkers Face an Unabated Roar” (https://www.nytimes.com/2012/07/20/nyregion/in-new-york-city...)

For more reading, there are articles for various cities linked at the bottom of this NIH page:

https://www.noisyplanet.nidcd.nih.gov/have-you-heard/noise-l...

small, busy restaurants without sound deadening can be really loud, but I doubt it's actually 90dB. that's like the opening band at a small music venue.