One possible way to force a bit of scrutiny upon NSO group would be to crowdfund an Pegasus subscription and use it against Netanyahu.

I think it's naive to think this has any chance to succeed. This company is in a close relationship with israeli intelligence. As close as imaginable imho. Every target is vetted. The "surveillance as a service" thing is only marketing. It's just a private intelligence agency hacking people for profit without any ethics.