For me, I think financial stability works behind our success in life. So same goes for Bitcoin investors as well. The rich person could invest for a long time. He doesn't have problems even he doesn't sell his holding even during very bear markets. A financially stable person even could hold 10 years. But like us who are small investors, we aren't stabled financially. As a result, we don't when we have to sell our holding for need. That's how we become losers even we intend to hold for a long time. I am a real example of that recently.
Mandatory? No. Helpful? Definitely. If you have financial stability that means there is a good chance you know what you are expecting from your own finances. Let's say that you have been working in the same company for a while, few years, and there is not that much of a chance for you to get fired right now, that means for a few more years you will keep working there by all accounts unless something unexpected happens and you can calculate your salary and make investments accordingly.
This doesn't mean that if you do not have any financial stability that you can't make any investment at all, there are still ways you can as long as you have some excess money at the end of the month.