No meaningful privacy can actually be obtained without either preventing entirely the ability to surveil you (not practical at all) or finding blind spots where you can "mix" yourself with other people and obscure who is exiting those blind spots in which direction. Without these places multiple people can go into, where they cannot be surveilled inside, and leave in different orders and exits obscuring who is who, no privacy can be obtained from surveillance. Preventing surveillance in the wider world is essentially impossible, but if you can prevent it just in blind spots people can use for this purpose, that is enough.