Running is better than sitting on the coach. But strength training is better than running. Why you should not be running , by Mark Rippetoe: https://startingstrength.com/article/why-you-should-not-be-r...
That article makes a good argument, but I feel like it misses the potentially more significant issue that running is an actively bad choice of exercise for a lot of people even if they want to focus on cardio. It's harder on the body than a lot of other cardio exercises, particularly for the target audience of things like "couch to 5k". It's definitely better for you than sitting on the couch, but only if you stick w…
The only exercise I can think of with a lower barrier to entry is walking. Every able-bodied person knows how to run, even if they can't go very fast or far.
Strength training has a higher barrier to entry - weight training requires a gym membership or your own weight room, and you have to learn to perform specific movements correctly and safely, which requires research or paying a personal trainer. Bodyweight strength training also requires learning many not necessarily intuitive movements. Other forms of cardio also usually require an investment in expensive equipment (eg. cycling) or a membership (eg. swimming).
Running isn't recommended to sedentary people because it's an optimal exercise - it's suggested because anyone can pick it up with minimal cost and learning. And it's more time-efficient than walking.