One can enter physically a theater and watch a movie without paying quote often. Depending on the timing and staff you may not be confronted for a long time or at all.
Does that mean theaters don't really care or obligate consumers to pay?
There is nuance because the behavior around physical spaces is well established by law and social norm. This is absolutely not true for the internet, as evidenced by this very debate.
If you will indulge the hypothetical, and we step back from the established social norms (people know you are expected to pay), who is responsible for making sure customers understand the need to pay? The theater. If the theater doesn't secure their doors and doesn't say anywhere "you must pay to enter," then it's a completely reasonable behavior for someone to enter and watch until they are asked to leave or pay. If they refuse to leave, they're trespassing. If they are told to pay before entering and they sneak in, this is clearly trespassing.
But this is not really the same thing as online advertising. Online advertising is more like, you ask them to deliver a DVD to your house, and the agreement is "we'll deliver the DVD if you also let us place a camera and microphone in your home to watch your reaction to the DVD." Then you allow the DVD in but refuse entry to the spy gear. It would be very problematic to try and force people to accept the spy gear, or prevent them from denying entry to the spy gear. It would lead to laws purposefully designed to deny people privacy and control over their own homes. A much better solution would be for the company to just not allow you to take the DVD unless you also take the spy gear and to create laws around that behavior if necessary.
Does that mean theaters don't really care or obligate consumers to pay?