There is always a fine line between professionalism and stick in your arse. Of course you need to know when such a culture is adequate and when it is not. If you work in support you probably don't banter with the people calling you. That would indeed be unprofessional.

Professionalism is to keep distance to others, banter is the opposite, as it is a form of bonding.

"Modern" workplaces that advertise themselves as such are very likely toxic. Might seem counter intuitive but it is often the case in reality.