DC-DC + LDO in series
Switching converters are generally more efficient than linear regulators, although there are circumstances where an LDO can be comparable or even more efficient.
Linear regulators can't produce Vout > Vin, only a switching regulator can do that.
Switching regulators inherently produce a certain amount of switching ripple at their outputs. So linear regulators are generally less noisy than switching regulators.
A combination of switching regulator with an LDO post-regulator is often used to achieve both decent efficiency and low noise. But efficiency is not as good as a switching regulator alone, and there is a cost in parts and board area.