But I am not in school anymore so why should I have to pay for that?

Guess who paid for your school while you were in it

Plenty of people have tried to make that argument. Those people typically wind up spending years of their life in prison once their delinquent taxes have built up enough (and losing the property that they were trying to avoid paying taxes on, also).

Anyone who tries to tell you that they've successfully argued in court that the law doesn't apply unless you sign a contract agreeing to it is either just plain lying or got lucky on a small enough case that the judge or prosecution just didn't want to deal with the headache.

By the way, keep in mind that property rights aren't a naturally existing phenomenon. You own your home because the state agrees that you are the rightful owner. Is a different system theoretically possible? Sure, probably, but the state-based enforcement of property ownership is the one that exists today.

Whether you directly use these things or not you benefit from them. Schools train people in the services you use or employ. Roads get all of your goods and services to you. You are not an island.

You don’t go to school, but the community you live in is improved by having kids who did. Less crime, more people capable of doing the jobs that make society run, etc.

Also, how on earth do you imagine “entering into a contract” for the roads you drive on? You’d rather have every single road be a toll road? I think that could easily end up costing you more.

What you are describing is neoliberalism in its base form. If you want to dice deeper I to it I suggest Saez instead of some 16th hundred philosopher. (I'm not too familiar with Lockes work, this is more about time than profession or person).

The reason why taxation works different than contract agreements is basically:

Taxes are used as normalization tool, both in the fiscal as well as the social sense.

In general you have three categories of tax: based on purchase, based on possession and based on income.

Most modern countries use all three in a combination. The reason why it's not purpose linked is simple: you can't organize it.

To give an example: How much worth does a future tax payer? And who benefits?

Based on the answer to that question you'd either tax consumption (because future tax payers will keep cost low), income (because production facilities for future tax payers is taken from the workforce) or possession (because future tax payers are the foundation of generational transfer).

And on top of that comes the big question of social normalizing effects: even very conservative counties tax higher incomes higher than low incomes to improve the overall Gini coefficient, i.e. achieve a bit of wealth distribution. Now you're fully in "opinion" country though: How much should society pay for its weakest or unluckiest?

And because it's not yet complicated enough there's one very simple element coming on top: "what can we get away with?". Rules, especially if taxation, are only meaningful if they can be enforced.

German highways for example have a dedicated tax for heavy transports for using those roads exactly the model you've described. 50 years ago that would've been technologically impossible to realize there.

Now using a sidewalk as an exame and it becomes messy. Because the people directly using them would be the obvious choice. But what about the shops closeby which profit from foot traffic? What about the reduction in micro plastic pollution because those people don't use cards (which produce about 1/3 of it). What about my body weight? I'm fat and will damage the ground a very tiny bit more than someone who's half my weight. And what about paramedics using it? The rulebooks and exceptions will be either: broad and easy to abuse, broad and they will exclude many people from using the infrastructure or narrow which brings both at the same time.

To come back to your example: you pay for school because it's the one institution that makes sure that our economy will work a few years down the road, having new consumers and taxable incomes which are needed for me to continue, well, existing. And you do have a verbal agreement: "I'm choosing to stay in the place I am". This binds you to its laws, including taxation.

Now if you argue that you'd just want to keep what's yours then usually just looking one generation back already makes that break apart: where did your parents income and education come from, what social structures did they benefit from, etc.

But: All of this is not intended as "taxes are good as-is". A) I have no idea what your frame of reference is and B) it's not in my opinion. But it's complex. Really really complex because the whole system changes depending on reference timeframe, social norm and the societies past and present goals.

Ultimately, it is cheaper for EVERYONE if we all just pitch in a little. You may pay a little for schools that you don't have kids to go to, but you pay LESS for things like roads, sewers, and trash disposal.

This isn't a min-max system where you can adjust to only what you use and come out ahead. If you try, you end up paying more. Not just in the services themselves, but in the administration and middle management of the systems to handle calculating who used each system and how much they used it.

So as a community, we all pitch in and we all benefit.

We should all be fucking PROUD to pay taxes. We should be proud that our money goes towards educating all the people around us. We should be proud that we have parks and schools where children can play, learn, and grow up safely. We should be proud we have fire and medical teams who dedicate their life to helping others and keeping them safe on the worst day of people's lives. We should be proud to live in places that are attractively maintained. We should be proud to spend our money on conserving the environment around us. We should be fucking proud to have libraries that lend out not just books, but tools and board games and toys. We should be proud that we pay so we don't have to live in sewage and trash infested places.

We should be PROUD to pay taxes.

https://newrepublic.com/article/159662/libertarian-walks-into-bear-book-review-free-town-project

That sort of thing was tried by libertarians in New Hampshire and it went boom.