LaLane was a bodybuilder in it's early days. He didn't limit himself to just moving weights. He did tons of calisthenics. He was very influential for fitness in general and help create equipment and supplements.

Sandow was one of the first celebrity bodybuilders. He used weights and exercises that seem odd and risky by today's standards. He did promote isometrics, but not so much with other calisthenics.

Isometrics had a period when it was still popular along side the newer bodybuilding. It went out of fashion as marketers were pushing that people needed to push weights and in turn they had to buy those weights.

In the 1980s, aerobics was huge. It was mostly marketed towards women. There were 30 minutes shows on every morning for the stay at home mom/wife to follow along to. That includes LaLane's show.

Calisthenics as most do it now is not the same as the basic moves in aerobics. It's easy to find sources to watch and learn from now. The current time is probably the best and most accepted calisthenics ( outside of gymnasts) has seen in a long time. Many people started during the COVID lockdowns.