Do you really need to arrive 2 hours before a flight?

Excuse me, I'm curious about something. The advice to arrive two hours before a flight is often given, but do we really need to do that? Isn't it a bit excessive, especially for short domestic flights? With the modernization of airports and technology, isn't the check-in and security process faster now? Wouldn't an hour or even less suffice for most travelers, especially those who have already checked in online and have minimal luggage? I'm just trying to understand the rationale behind this recommendation.