And always remember that a very large percentage of so-called "electronic failures" are actually contact/connection problems, so you should not only back things up in case the card is failing, but also make sure the tiny contacts on the card are clean.
People often handle these cards with bare fingers touching the contacts, and transfer finger grease, hand lotion, etc to them. It amazes me that these kinds of contacts work as well as they do.
These micro SD cards are difficult to manipulate because they are so tiny. It makes it hard to avoid touching the contacts.