The Benefits of Running a Tempo Session

Run walking can be from the walking between a very hard interval session. You could count that through to race day strategy being that actually you might get a better marathon time if you factor in a bit of walking now and again. I think there's always this stigma, isn't there? When I'm doing a tempo session, it says walk for a minute and a half, I think, oh no, I just jog that and then I'll look better on the Strava. But you're running coach, so you know a lot more than me. So what are the benefits I guess for doing it like this? It also depends on how much time you've got on your hands.