Are there too many conjuctions in the sentence?

Although some studies find that hosting refugees may be economically beneficial because of their participation in the local economy, the largest benefits are in the long-term, whereas hosting costs are sustained immediately and are thus more politically salient"

It seems to that in the sentence, one of "Although" or "Whereas" is unnecessary and that makes it confusing and I couldn’t understand the exact meaning.

Could you help me about the explaining of the sentence?