If cider has been around in Western civilization (e.g. in Europe or the United States) for centuries just as much as wine or beer, why has cider been less popular, especially in the past 75 years or so?
To put it another way: Why did cider not recover after Prohibition as much as wine or beer - differences in alcohol content? Greater popularity of beer and wine among many immigrants to America (from Central/Eastern Europe and Italy respectively)?
Also, has mead not been as popular in contemporary times in the West as wine or beer because mead is much more expensive?
If cider has been around in Western civilization (e.g. in Europe or the United States) for centuries just as much as wine or beer, why has cider been less popular, especially in the past 75 years or so?
On the whole cider was never as widely popular in Europe as wine and beer. It had its very strong niches in places such as northern France and England where grapes struggled to adequately ripen but overall beer and wine were more popular over the whole of Europe. Beer was popular because grains are relatively cheap and beer can be brewed for much or all of the year depending on climate and grapes produce higher alcohol and wine is fruitier and less astringent after fermentation.
Cider was indeed popular in England though and the colonists who came to America brought there love of the drink with them when they settled here. Cider requires certain type of apples to make that are otherwise unpalatable so when prohibition hit these cider-specific apples were cut down to make way for other crops which would often include dessert apples. Without the raw ingredients available the cider industry didn't have much of a chance after repeal.
Another thing that I personally believe effected cider was demographics. Cider was popular among English descended rural dwellers, beer especially popular among German immigrants and wine with those from southern Europe. The English-derived protestant rural people were the ones who pushed hardest for prohibition. Hard core whiskey drinkers of any persuasion did not want prohibition but the I think the cider drinking culture was lost to a large degree. The Italian wine drinkers and German beer drinkers were largely against prohibition and did not loose their drinking cultures.
Also, has mead not been as popular in contemporary times in the West as wine or beer because mead is much more expensive?
Despite what Dunegeon and Dragon campaigns may have us believe mead has never been very popular relative to wine, beer or even cider. It had its regional hotspots in places such as Wales, Scandanavia and Poland but even in those locations its high cost to produce relegated it to a luxury item.