I'm afraid that a lot of idols, or a lot of people that try to lose wight, aren't taught how to properly do it, instead they are usually told to try unhealthy ways so that they don't understand the basic concepts of how it works on long term. When you lift weights you don't lose that much weight if you are already thin enough, instead you build muscle and lose skinny fat, but you can weight more than how you originally started, even if your body looks leaner. That's healthier then not eating and losing just weight itself:

Dieting: Looks like weight loss mainly losses water, short term, loss of muscles which in turn makes them more tired, unable to dance, dizzy, may lead to yo-yo dieting etc.

Proper weight lifting + healthy diet: takes more time, losses fat, gains muscle instead (60kg of fat vs 60kg of muscle), healthier on the long run, less chances of skin sagging etc.

She looks fine as is. This whole culture of losing a lot of weight in a short time is really unhealthy and will lead some into eating disorders just trying to obtain it.