As someone with a medical degree, I'll answer that. It's neither, unless you can get a proper fitted mask, don't fidget with it and dispose of it once used. Surgical masks, cloth masks, and distributed n95 masks don't fully protect yourself against the covid virus. The n95 masks only protect against .3 microns and larger, the covid is .06 -.15 microns. Do they help? Slightly. However, if you watch how people "use" masks, they're pointless. In the hospital, we have to be properly fitted for an n95 mask and clean shaven for males.
So, in short, yes they can be beneficial to your health, if a proper mask was used the way it was supposed to.