Apple watch does not register workouts as it should, when compared to other. When walking next to other people their watches register much more for training and calories. It also does not remind to start a workout when other watches do.
Apple Watch Series 3, watchOS 7
A brisk walk speed is different for everybody as the watch takes into account your age,sex,weight and heart rate which why it is important to calibrate the watch when you set it up from new,the idea being that you're being encouraged to put more effort in to walk faster and to get your heart beating faster, if you just walk at a slow pace then you are not going to improve your fitness or get all those award badges that we all seek.
Watch app/workout/start workout reminder is where you turn the workout reminders on and off.
Apple Watch workouts
