Why does depression of freezing point takes place if a non-volatile solute is added to the solution?
A simple "intuitive" oversimplification: intrusive foreign molecules get caught between solvent molecules, getting in the way of crystallization. That, however, would contradict the similar boiling point elevation.
Another oversimplification: the solute molecules pull the solvent away from the incipient crystals.
Yet another simplistic answer: osmosis exerts a force on the solvent, pulling it back into solution, away from the pure crystal of solvent.
Perhaps the last explanation is closest to a statistical analysis of freezing point depression.
Hopefully, chemistry will not be a depressing subject.