That never worked.

Google had Google+ which was a massive failure.

Facebook tried releasing a product for workplace communication named Workplace/Facebook at Work and that is almost dead.

Microsoft has been eyeing a social media platform for years, and the only relevant product that I am aware of is Viva Engage (formerly Yammer) that is not very good in my opinion.

Oracle has never ever had any product that targets mainstream consumers. They always focused on enterprise products and don't understand consumers. Just like Microsoft never released a hardware product that matches iPhone's success, or Apple never has any enterprise product that remotely competes with Office. It's not in their gene. They'll be lucky enough if they don't run it into the ground.