Garage door rollers are a very important part of your garage door. Each garage door roller has ball bearings in them. If I had to compare them to anything, it would be a skate board wheel. Every kid knows if your skate board goes in the dirt, the wheels do not want to roll, because their is dirt in the bearings. After a couple of years, the wheels will get wobbly as well, because they are wearing out. Besides the issue of noise, when your garage door is going up and down with old garage door rollers, they can cause damage to other components as well.
A broken roller caused this panel to come off of the track, which then ruined the panel.
A old wobbly roller caused the hinge to bend and break. Rollers gotta roll!