See: https://www.mrmoneymustache.com/2012/05/29/how-much-do-i-nee... and https://www.reddit.com/r/financialindependence/
Insurance at it's core is amortization for individual risks you cannot bear the burden of, but as a group people could. Things like illness, accidents, disability etc. I recommend you get a fiduciary and explore insurance for the risks and annuities if you want to remove risk around your income too .
For most people the challenge is that they're running much higher than 15% of their pay. So it takes forever to get the equity required to no longer need an income stream (AKA job)
I think we all worry about this; some are more frugal than others.
However, I know I didn't really worry about this the way I do now until I started having a family.