Government regulation is not necessarily the dictating of behaviour to strangers.
Every collective has it's own rules which are mostly designed to facilitate better running of the collective. This is true from the couple, the family, the business, the church, right on up to the planet as a whole.
It is imperfect to assume that everyone will agree to get along and abide by the same rules. Therefore, you need a level of collective creation and agreeance of rules in order to try and optimise behaviours.
Once you decide that there needs to be rules, you've got to decide on who makes the rules. There are many choices, from outright dictatorship to various levels of democracy.
So in a sense, we surrender ourselves to certain rules in the understanding that we consider the cost to be greater than the benefit. This will always involve compromises - but in a truly free society freedom to stick up massive advertising hoardings conflicts with the freedom to walk down the street without having to see such things.
The middle road, the compromise, is a representative government whereby we agree to rules in the understanding that, if the rules aren't working out in the way we want, we collectively change the rulemakers.
Of course, in practice, there is plenty of evidence that this is problematic. For the most part, there is far too much government regulation over matters which the government has no part in agreeing to.
In the case of the advertising hoardings - well, presumably whomever enacted the ban would be free to be challenged in an election and the decision overturned if people felt the cost exceeded the benefit. In this case, I don't really think it's a case of violating free speech, as the advertisers are still free to speak in many forms, just that there are restrictions in a certain form.
But a dogmatic sticking to an approach where nobody has any say over anybody elses business just invites ridicule, just as communists and socialists of varying stripes invite their own ridicule with ridiculous 'property is theft' comments.