Maybe the positive is that access control might break the illusion of privacy.
Okay it's quite private in the sense that we don't know our friends browsing history but we know somebody, somewhere is collecting data and selling it to their 100 partners.
Do you think there might ever be a moment when someone decides, legally or not, dump enormous amount of info, in a way that allows people to see what google searches other people did or browsing history etc? A moment when people's embarrassing secrets come into light.
Saw a mini documentary once, which was filmed in China, that showed how easy it was to buy this data. Many apps spy on location and sells it to brokers. In the documentary, they showed a common practice: people buying their romantic partner's location history to make sure they haven't been doing anything naughty.