On paper Dosage is easy to understand, on the palate it is as everything is with Champagne, extremely complex. Zero Dosage can be seen as a trend supported by producers and sommeliers, for whom terroir is the holy grail and any Dosage no matter how small is seen as betrayal. At the same time climate change plays a part, the Champagne has become warmer, grapes are ripenening earlier, there are fewer bad vintages which means the need for high Dosage is not necessary.
Also tastes change and how we drink champagne play a factor. As an aperitif or without food as a partner, a certian amount of Dosage is advantageous. Where Zero Dosage or Brut Natur comes into its own is with food pairing. Champagne made with Chardonnay or Pinot Blanc is as good a partner to haut cuisine as white Burgund, Riesling or Chenin Blanc can be. Obviously the style of Champagne and where it comes from plays a large part in what types of food are suitable. Richer Champagnes from the grand cru sites of the Côte de Blanc are going to work better with Bresse Poularde, Turbot, Scallops etc than Chardonnays from lesser sites.
Similiarly the red wine based champagnes can easily be paired with foods where a red Burgundy would work. A recently tasted Reflet d'Antan from Bêreche had identical structure and aromas as a Pommard.
As with other wines a lot of experimentation is required to find the styles/producers that suit the individual palate.
What I find curious is how prominent testers award big scores to champagnes. Big champagnes like Salon, Cristal etc get high points where the dosage is often in the upper Brut region, and Champagnes with little or no Dosage are awarded lower scores. As someone who has the chance to take part in many profesional tastings, tasting 100+ wines in one day is challenging, tasting 30+ Champagnes in day is not advisable. Just as in wine tasting richer, more fruit forward champagnes are more appealing, zero brut or brut nature can come across as tonicy and this is probably reflected on how points are issued. Also take into consideration, a tester takes a sip and spits it out and with their highly attuned palates are capable of detecting aromas where mere mortals detect nothing. Were they to drink a whole bottle over the course of an evening, how would their cocksureness in making absolute pronoucements stand up to their initial assessment.