Is any job really steady this day and age? For the most part, positions in the entertainment industry are freelance. There are some studio and agency jobs that are contract jobs, but the reality is, nothing is truly stable in this industry.
Some people are fortunate enough to get on a series that lasts for ten years. They, unfortunately, have their own set of complaints.
If you were a teacher or a janitor and had tenure, your union would protect your job. In the entertainment industry, a union protects your contract and safety. An entertainment union can not guarantee/secure a job for you. Basically, you are a business owner, so the success of your business depends on you.
Knowing this, I suggest multiple streams of income.
If you have a question, put it in the comment section.
To your success!