Presumably depends on whether you have a device to do it for you. Since I wear a watch anyway, it’s dramatically simpler to let it count steps for me.
Steps are more convenient if you own a smartwatch or health-monitoring watch.
Most people don't ("but I never see anyone without one!" yes, you live in a tech-hub bubble), so yeah, time would be easier.
A normal pace for me is about 100 steps per minute. It’s a convenient way to estimate steps taken.