You didn't consent to a shopkeeper putting a price on his goods, but you still have to pay it. If you assume that there is a cost to produce goods, then it's not too difficult to see taxation as the price we pay for goods produced under Government. Yes it's more complicated than that.
One question, maybe the most important, is whether Society could function with no Government "goods" at all. I had a discussion years ago with an extreme Libertarian who seriously claimed that the country should function with no government at all. I mentioned the police and he was happy with the idea that local communities could have their own laws and police. I suggested that it would soon result in a collection of local "war lords" attacking each other, but he was unconvinced.
Too extreme, you say? But any Government function would involve taxation. Do you want private armies, each defending it's own section of the population? I can't see that working well. You said "essential services" . Is the army not essential?
My first point is then that some Government services are truly essential, and thus taxation, or some other way to get the recipients to pay for them, is also essential.
If you meant to narrow the services Government provides but not to zero, I suggest that some services are best provided centrally. The example you gave of roads is a good one. We do have toll roads, but there is still a question of how many roads do we need to connect point A to point B. One is the answer in most cases. So how do we decide which private entity will build any given road. You can't have them all build roads and let the market decide. So we need an independent body to decide between competing bids and designs. Could that be Government? Then it needs to be paid for....
Broadening it a bit more, there are things like healthcare that work in the private sphere, but tend to favor those most able to pay for them. Here we enter a more contentious area, because you need some altruism to have a system where amounts paid do not directly relate to the services received. Most people are OK with helping those in need to some extent. Government and taxation again.
(By the way, I can argue that universal health care is not unselfish at all, but that's another topic.)