I'd say the major switch happened at the point where you lost control over your feed. It's not populated because you opted in to updates from a specific person or organization. It's populated by algorithm. Furthermore, at no point in time were any of these new features opt-in. Instead, they were enabled without your consent. Facebook has a long history of enabling features for people which is not in their interest in the slightest.

I should also say that it's more general than Meta. Google are also notorious for doing stuff like this. About time we start legislating against it.