Many times Mercury is too close to the Sun so it is lost in the glare next to it. Mercury is usually pretty bright because it is so close to the Sun and not that far from the Earth. Apparent brightness depends on size, albedo, and distances from Sun and Earth. Mercury is only a bit dimmer than Saturn now.

The larger the elongation of Mercury from the Sun (currently 20 degrees) and the closeness of other objects (Mercury is west of the star Regulus in Leo, the easier it is to see Mercury. Sometimes I use binoculars first. Once you know where to look, I can see Mercury with my unaided eyes.