Generally you have to get off your seat during stops. Or you can get to the curb so your foot has a platform.

Some bikes have a lower bottom bracket so you are closer to the ground by default.

I lean my bike to the side a bit so one foot will be flat, and move the pedals so my go foot is bent at the top of a pedal. Then jump on the seat with the first stroke. My seat is not very high and my bike has a low-ish bottom bracket.