Technically yes, but our system is not single payer, it is payed for through taxation. At some point the amount of taxes a small percentage must pay to support the majority is no longer viable, people either won't be able to survive or they will find ways to take their money/business etc. elsewhere. So technically percentage is not the factor, the taxation on that small percentage in order to maintain the needed amount of revenue will be. Then what happens? There is a tipping point that the system is unsustainable, what is it?