I left the ward to build the thing I kept complaining about

I complained about agency staffing for a decade. At 41 I finally stopped complaining and registered a company.

I had eight months of savings and a plan that assumed everything would go right. Nothing did. Month five I nearly went back.

What saved it: one hospital manager who took a chance on us, and the fact that I knew the actual work. I could not sell, could not do books, could not hire. But I knew what a bad rota does to a ward at 3am, and that turned out to be the whole product.

If you are leaving a profession to fix it from outside: your expertise is the asset. Everything else is learnable, and slower than you think.