This is a beginner question. I know how the logic gates with BJTs work basically to provide ON and OFF switching action. OFF state occurs when the transistor is blocked in cut-off region, and ON state occurs when the transistor conducts between the collector and the emitter.
So ON state occurs in both active region and the saturation region. I wonder in logic circuits why better to saturate to obtain ON state instead of conducting in active region? Active region seems to be avoided. Is that for stability or heating? Why?