There is advantage for SMD components specially at high frequency and switching because the leads are shorter decreasing parasitic impedance/inductance.
In addition the small packages allows for tight power design because components can be places next to each other which also decrease trace length and power loops.
As far as i understand it this leads to less noise, EMI , and oscillations hence a better product.
Although Military applications still use through hole (in some designs) and NON-LEAD-FREE components and process, because they have advantage in resisting vibration and shock in harsh environment. (This is a mechanical advantage over SMD)