Doesn’t forcing Facebook to be interoperable go against free market principles?

Free market principles would require markets to be open and contestable. However, at the moment many markets for digital products and services are dominated by gatekeeper companies that have achieved an unassailable market position by relying on the sheer size of their existing user base to keep their users (so-called network effects), without having to compete on the merits of their products and services.

In practice, new operators cannot break into these markets and any company showing signs of doing so risks being bought by the gatekeeper (see for example Facebook’s acquisition of WhatsApp and Instagram or Google’s acquisition of maps app Waze). Interoperability requirements can be a tool to restore free market principles, where markets are open and contestable, and where companies have to compete for market share on the merits of their products and services.