If you walk a moderate 100 steps/minute, 49 minutes of walking is just 4900 steps which is easy to hit without even really intentionally walking anywhere, unless you work from home without going outside
Put some headphones on and walk. If you live outside of the city you have even more nature to walk in.
Also note that they were wearing hip pedometers, which might overestimate "moderate" exercise compared to something that also tracks heart rate.
Moderate exercise, plenty of people are on their feet all day for work.
WFH is 10x better because all the commute time can be transformed in walking around the block or exercising at home instead of being in a car or public transport.
People will naturally do that 5 days a week working in a city, there's no "well just go take a walk" handwaving.