Imagine you’re watching a movie, and the main character turns over to their bedside clock and it shows 4:13 am. With time zones we all understand what part of the day that is and instinctively can relate to the situation.
Without timezones, every locality would have a different shorthand and cultural understanding of what times mean what. Or they’d adopt a second system that helps transcend that but that’s just inventing timezones again…