There's lots of animals that humans are trying to increase the populations of. Pandas for example.

Surprising as it might sound it could very well be that there is no real intent to increase panda numbers because they are needed in low numbers to generate funding for other things.

Conservation groups are the ones who decide where their funding is spent, and more precisely what animals is it spent on. The general public are more often than naught donating to the conservation groups as a whole, not "I want Penny the Panda to have a new tyre swing". This is largely because the general public likes cute and fluffy animals as there is a far greater affinity towards Mammals as a whole than other taxonomical Classes like Reptiles, Amphibians, Avians and various other Chordates before even considering other entire Phylum like Arthropods.

So species like the Giant Panda get pushed to the front as the poster child for generating funding through donations because if it was tried with other species which were equally in need of funding or even more in need, like some species of newts, then the money wouldn't happen because mammals > amphibians to most.

It's basically a grift the conservation groups have to pull on the general public because said public cares more about how the animals look rather than whatever ecological importance might be at hand.