Do some contracting / consulting for a future employer first; and then ask if they will take you on as a regular employee? As for how to evaluate. Try imaginin

Do some contracting / consulting for a future employer first; and then ask if they will take you on as a regular employee? As for how to evaluate. Try imagining a 5-10 year period in both scenarios, calculate your pay/earnings, be realistic about sick leave, holidays, periods without earnings (as self-employed), figure out where you will be career-wise as an employee. I can absolutely understand why being an employee again can become attractive again after a while as self-employed.