Financial stability is desirable because it can do a lot for us, and can open up choices in life.

It can enable you to be financially independent and not rely on external support.

You can take care of yourself and your closest people with greater certainty. 
Food, shelter, clothing, healthcare, education and so many other things we need for a better life rely on us having the financial capability to pursue those things.

It can allow you to switch your career function or industry, take a career break for personal reasons, or even start something on your own.