Every cartridge has a specific tracking force specification, usually ranging from 1-3 grams. Using the tracking force indicator on the tonearm is usually inaccurate and fiddly.
Dialing in your correct tracking force is absolutely essential for optimal record playback. If you miss on the heavy side, your sound becomes thick and sluggish. Miss on the light side, and your cartridge is more likely to mistrack and the sound will be light and anemic. A dedicated stylus force gauge (best option) will enable you to set the tracking force as per the cartridge manufacturers specifications. This will prolong the life of the cartridge and get the very best performance from it