Yes! It is absolutely true that you can be successful in SFI even if your PSAs and CSAs have stopped working. That is because if your PSAs and CSAs have stopped working, you will lose income from only ONE very vital income stream whereas you can still be earning money from at least THREE other income streams besides that one. That is the singular reason why you can still succeed in SFI even if your PSAs and CSAs have stopped working.
Having said all that, I am quick to add here that it is always best to earn income in SFI from ALL the available income sources. It is therefore not advisable to lay back and relax if your PSAs and CSAs are not working. Even though you can succeed without the income from that one source, you will succeed better if you are able to earn income from ALL the available sources including income from the activities of your PSAs and CSAs. That is why you must try to get your PSAs and CSAs back to work through resourceful and meaningful sponsorship if and when ever they stop working. That is the best advice I can give in the circumstance.