Wilde has made us laugh for over 150 years, precisely because his universal message is clear: The masques men wear bring out their true identity.
In this play, the universality of the masque is the elitism and hypocrisy of society, which allows the reader to read between the line and see the true make up of each character.
Those same situations happen in the 21st century: False images, elitism, marriage for all the wrong reasons, interest in money and financial belongings rather than the true nature of character.
The satire Wilde presents in his play seem all too relevant to society today. Wilde pokes fun at the morals of the upper class. While it's true that there are many philanthropic millionaire and billionaire, we are more drawn to the upper class (celebrities) behaving badly--it's more fun to watch that and gossip about that.
The other social institution that receives a great deal of satire from Wilde is marriage. He insists that people get married for the wrong reasons--for show and social gain, more than anything. Though those might not be the reasons people get married today, marriage is a failing institution with the divorce rate near 50%. Wilde views of marriage being view under the incorrect lense--perhaps people aren't thinking it through or are doing it because they feel they have to--is still relevant today.