Let’s start with recalling the definition of Friction. According to scientists, friction is a force that resists. So if seen superficially, you’ll think of it as what you called in your question “bad”. But, science says, not all resistance is bad. In fact, with the point of view of Physics, this resisting force is inevitable for quite a lot of our daily activities.
If you know the reason of you shoes having groves, or the road made rough, you’d understand how important the force of friction is. Obviously, no one would like to slip on a wet floor, or a tiled floor. These types of floors are slippery because they lack friction unlike roads. So in this case, friction is undeniably desirable.
Let’s take another example. The first law of motion
states that an object would never stop its motion until and unless it experiences any outside force. So to stop, or change the motion of an object, more often than not, the external force applied is the force of friction. Similarly, force of friction is used for everything like walking, running, holding something in hands, or putting something on table.
This is the positive side of friction where friction can be said as good. In some cases however, friction act as undesirable. For example, in the parts of machine
, force of friction causes heating and wearing of the parts and we have to use the lubricants. Sometimes we even have to change the parts for new.
Henceforth, it’s the situation which makes friction good or bad. Be it anyway, we can’t this universal force which is present everywhere.