Mining veins and herbs spawn rates

Hi everyone, i'm kinda new to the server but couldn't find anything on this topic on the forum.

I'm leveling up and i picked up Mining and Herbalism, but what i noticed, in basically all zones so far (i'm level 57), is that the veins and herbs are really difficult to find compared to what is reported on sites like WowHead.

I also noticed that this is true even when i play on hours with "low" population and i'm basically alone in a given zone.

Any reason for the low spawn rates of veins and herbs?

Thanks for the help