What is also unstated is the concept that these things can only be provided via a coercive monopoly. Only one entity can build a thing or do a thing (post office) and you will be forced to pay for it and/or not allowed to compete. Even though there is much historical evidence of all manner of nominally only-government things being provided on a voluntary basis such as roads, the post office, currency, education, dispute resolution, product standards, apprehension of malefactors and so forth.
Plus, the whole concept ignores the price system. The people who had input into whatever business at whatever remove were compensated for their efforts. They agreed to whatever reward and took it, that ends their claim. Now, people who are taxed to support the infrastructure do not have any additional claim because they too could have used said infrastructure provided for their own needs so have already received an equal share of the benefits.
All of this is just another slimy way to weaken property rights and put more productive assets in the hands of the political class and their hangers-on. The net result of this line of thinking IS socialism and the debasement of all productive elements eventually leading to a wasteland where there was once a viable country.
It is the mindset of the weak-minded, the gullible, the unethical and the lazy.