Why track loaders?

I'm not trying to start an argument. I'm only trying to understand. I feel that track loaders were common at an earlier day than articulated wheel loaders. Why? A wheel loader is faster, costs less to operate. What factors led to the development of track loaders in the first place.

There's a fellow here with Backhoe, and Drott bucket on a 410 Deere. That makes perfect sense. A single machine able to do a multitude of tasks. Far more common were GP buckets on tractors primarily designed...

Why track loaders?

Why track loaders?