An ADC value tells you a thing about the world. A number on an LCD turns that into something a human can read. Add a unit, add a bar, and the device feels finished — even though all you've done is read a pot.
Scale first, then display
The raw ADC value (0–1023) is rarely what you want shown. Scale it to a percentage (0–100) or a real unit (millivolts, degrees, distance). int pct = map(analogRead(A0), 0, 1023, 0, 100);. The LCD then prints "Pot: 53%" — instantly intuitive.
For analog things, bar graphs help. The HD44780 has eight custom-character slots (CGRAM). You can define a single "full block" character and print a row of them in proportion to the value. for (int i = 0; i < pct/10; i++) lcd.write(0xFF); gives you a chunky ten-step bar in two lines. Most "data display" devices you've ever owned are doing some variant of this.
The discipline of a unit label
Always print the unit. "53" alone could be percent, degrees, samples, kilograms. "53%" is unambiguous. This habit costs nothing and prevents a category of mistake that has caused real engineering disasters. NASA's 1999 Mars Climate Orbiter was lost because two teams disagreed on units. Your dimmer won't crash a spacecraft, but the discipline is the same one.