Why? Because even for the least knowledgeable and trained airline agent, a passport is universally recognized as an acceptable travel document. Irregardless [sic] of what is required or what Timatic says, airline agents might not recognize that a national identity card is an acceptable travel document and they will not allow you to fly.

For example, my USA passport card (which is a defacto national ID) will absolutely get me admitted to the USA if I show up at a POE. But no airline will recognize it as an acceptable travel document to board their airplane departing for the US.

Only you can answer the following question: is the inconvenience/cost of renewing your passport worth the inconvenience and cost of an ignorant airline agent refusing to allow you to travel?