Private Keys for Trezor

I hope someone can answer this question. I understand that every bitcoin wallet has a private key. But I just realized a trezor has multiple coins but still only one private key how does that work? Does that mean I can only recover my wallet with a trezor device? and will the private key provided even work on a different wallet?

TLDR: why isn't a private key provided for every different coin on a trezor wallet?

Private Keys for Trezor