I think one of the many disadvantages is that it is sometimes hard to breathe with the mask on especially when doing something that requires more assertion. The fact that it covers the mouth and the nose can be uncomfortable for some people. I have noticed that ladies who use lipstick and makeup tend to find it messy. It can get sweaty at times if you live in the hotter part of the work. For the fashion-sensitive, it might not always look fashionable.
That said I believe the advantages outweigh the disadvantages. Staying healthy and safe is always number 1.
If it can be made less 'intrusive' that would be ideal. If one can we a mask and feel like they are not wearing one...I don't know how possible that is...
When wearing a mask my glasses often fog up very easily, a real problem while driving. Masks are also a challenge for those wearing over-the-ear hearing aids.