Walking is not time efficient, you're better off doing 10 mins of HIIT than an hour of walking.
Sometimes the practical solution isn't the most efficient.
I mean if you're chatting with coworkers and relaxing during the walk then it's a different story - but if you're just in to it for health benefits - like I've seen people suggest walking home from work, etc. - just take the shorter route and do proper exercise.
Threre are a couple health benefits that walking has over HIIT. For my particular case, my doctor told me that the amount of time I sustained an elevated heart rate was more important than how hard I pushed myself (don't try to walk the same distance in a shorter time, instead walk for longer). And there are cognitive benefits unique to walking [1].
I can't speak for anyone else, but waking turned out to be my gateway drug to all kinds of other healthy lifestyle changes.
[1] https://www.theatlantic.com/health/archive/2014/10/walking-f...
It will likely require a shower afterwards though which might pose a problem.
1) A 60 degree F room to stave off sweating
2) Enough exercise to be healthy but that stops just short of making you sweat
3) (2) is variable based on body weight of course