Most mesh material is made of a polypropelene or like material that doesn’t hold up well, if at all in a crash. What you’re counting on is the armor to provide protection. In many instances, especially around town, this might be perfectly adequete. I have found however, that a well vented jacket/pants combo or suit and be even more effective, particularly at speed. The reason for this is that mesh allows a huge amount of air to blow across your body, taking with it your persperation before it has a chance to cool your body. Also, when it is very hot (90 degrees +) you’re getting blasted with hot air! Not only that, that mesh has no reflective capabilities to divert the sun’s hot rays.
Think of a well vented solution as a “cover” or shade structure and your motorcycle speed as providing the breeze. You still perspire, but the controlled breeze through your jacket doesn’t blow it away before it carries heat with it. You could think of mesh much like standing in the sun and blowing the hair drier on your body.