Blaming Facebook for "loss of democracy" would be ridiculous.

Democracy is being lost when you start having low turnouts. When citizens lose interest in the matter of the state. When certain positions essentially always stay in the same family(ies). When there is zero confidence in the ability of the politicians to run the country. When it does not matter who you would vote, because the end result (for you) will always be the same.

Loss of democracy is a process, not an event.