This is very true, IF you can get over the psychology. I passed 5y of savings and investments a long time ago, but my relationship with money changes dramatically depending on whether I have good cash flow or not.
After a while it can feel Sisyphean. Just when you secure more recurring revenue, you lose an old customer or get slapped with an unexpected large expense. One step forward, two steps back kind of thing. Every day.
So, it's easy to preach very sanctimoniously about the paramount importance of good money management as a self-employed person, but it's another thing to do it, and I find that's true for a lot of self-employed folks. Back when I had W-2 income, I really had it together; great credit, putting away $1k+ every month, all bills always paid on time, etc. Since then, not so much, and it's not because I suddenly got massively profligate. You just give up trying to put the ducks in a row when life keeps sinking them over and over.