Firstly, the most essential item, Food. Earlier rare & diverse dishes were prepared only in palaces or houses of the wealthy by specialist chefs. Eating those was a pipe dream for the hoi polloi. Now the common man can savour those dishes at least once in the restaurants even in small towns.
Regarding clothing, silks & woollens favoured by the rich, are inferior to the current synthetic fibres both in appearance, durability & affordability. How can the earlier clothing, which would wrinkle after a single use, compete with the "drip-dry" wrinkle proof synthetics? The commoner now may well be better dressed than the earlier royalty. Costume jewellery has made even the indigent girls vie with the earlier princesses!
Many huts have been replaced by pucca houses. Public taps, bore-wells & electricity have brought cleanliness & light to everyone. Even slums now, with their electric lights, are better lit than the torch lit palaces of yesteryears.
Education & Culture are within everyone's reach. Especially Philosophy & Scriptural knowledge, once the domain of the few, are now thrown open. Classical music, once reserved for the ears of the royals & the rich, can be heard universally. Classical dance & Art meant for royal eyes, can now be feasted upon even by plebeian eyes.
From this viewpoint, the common man of the 21st century has the opportunity to lead a better life than even the erstwhile royalty.