I'm trying to decide whether or not I should open up a second credit card. The primary reason is to have a backup credit card in case my only (and oldest) card is cancelled/eliminated for any reason. Length of credit history is 15% of your credit score, and I do not want to put all of my eggs in one basket. The second reason is to simply get a credit card with better rewards.
Currently, I pay my credit card off in full every month, and have done this for the past several years. I also have a car loan and a student loan (I'm not sure how these factor into my credit score). My credit score is 760+.
I'm aware that opening a new credit card can temporarily hurt your credit score by being a "hard pull" against your credit score, but what I'm more concerned about is that the second credit card will cut my "average length of credit history" in half. As an example, if my current credit card has been open for 10 years and I open up a brand new card - my "average length of credit history" will plummet from 10 years to 5. Is this a reasonable fear?
Aside from that, is my rationale valid for wanting a second credit card? Or is it safe to ride out one credit card for life?