I live next to a large hotel complex and I see lots of different groups attending events. What people wear varies wildly, yet they all manage to come across as reasonably professional. This can include the tech bro in a T-shirt, a woman in a dress, the guy in business casual, the biologist in a sweater, the property maintenance-con guy in jeans and a shirt. At accounting-con people tend to dress like accountants, at forestry con there really are all sorts of looks. With all these looks the people look sensible, professional and representative of whatever organization they come from. They tend to dress in what they feel comfortable in.

I don't understand why we are stuck in optics hell. People want to dress like an 80s conservative, people want a LARP-uniform from Germany, people want to all wear the same shirt and pants, some people show up wearing clothes not meant to be worn in public. If the dog show, the travel agency-convention, the electronics convetion people can look normal without having a dress code so can we.

The sensible dress code is wear what you would be wearing if your job sent you on a course.