Cynicism is cowardice, but cynicism is also a powerful tool to help you not accept things at face value.
If you’re cynical about a company selling you their mission, this allows you to peer through and see the actual dynamics; who’s calling the shots, and why.
If you’re cynical about anything and anybody, that makes it much more difficult to deceive you.
As with most things, it’s the dose that makes the poison. If you hide behind cynicism and use it to be cool: then yes, cynicism is cowardice. But if you are cynical, but still truth-seeking, committed to a moral framework, mostly earnest, then that’s good.