The alternative to the current model is not to have no services at all, as that makes no sense, agreed.

> The libertarian notion that taxes are extortion is frankly childish in how overly simplistic it is.

The argument is weak because you constructed a straw man. The libertarian notion is not to live without any of the services provided by a state, but to have different providers which are in competition. The issue is that the state / gov has a monopoly but is exempt from antitrust laws.

The implementation is tricky though because in reality, when functions of the state are privatized there is often a huge amount of lobbying and corruption involved and these functions are given to a small group of big companies which effectively form a cartel once again. Then they extract all the economic value left in the infrastructure, the privatization is declared failed and undone, effectively another channel of syphoning tax money into the hands of big companies.