Opera and classical music are simply no longer the popular form of musical theater or music.
Stage musicals (Hamilton) and film musicals (anything from Disney) are still very popular.
Popular music concerts (Taylor Swift) are obviously incredibly popular, and they're usually not symphony concerts.
While popular tastes have largely diverged from classical art music, a good deal of "popular" (and often excellent, in my opinion) symphonic music is still being produced and listened to as film music and game music.
Were they ever "popular?" Hasn't Opera and Classical long been the domain of the highly educated and elite? The more intellectual among the middle/lower class only receiving via recordings, radio, charity concerts, and community ensembles?
They struggle right now yes, but the major organizations in the great cities (London, New York, Los Angeles, Vienna, Berlin, etc.) all seem to still stay afloat.
Opera used to be rather popular, back before there were recordings. Opera stars like Jenny Lind and Enrico Caruso used to be a big deal, and played to packed houses. Every city had an opera house, even quite small ones.
Ballet and classical music were similar, as was classical theater like Shakespeare. They would be presented by touring companies, as well as community groups.
I think that recorded media played a key part in displacing them. The older forms, in their most expensive incarnations, remained as entertainment for the wealthy, as a way to distinguish themselves from the masses who watched recorded entertainment.
But a lot of grand old movie theaters started life as opera houses and classical theaters. They used to be popular entertainment.
I think another reason for their failure is the same reason the bottom has fallen out of the antiques market, because of changes in the culture, people don't have the respect for the past like they used to. Toppling of old statues, renaming of all sorts of things to have no connection to the past or history, the rewriting of history in popular shows, etc, are all sort of extreme reactions against the past and tradition and it's reflected in a fall in demand for older culture.
It must be horrible if a story of a fight explained all the world you know all your life giving you conversation airsuperiority.. and then that story starts to fade out while you are in it..
Stage musicals (Hamilton) and film musicals (anything from Disney) are still very popular.
Popular music concerts (Taylor Swift) are obviously incredibly popular, and they're usually not symphony concerts.
While popular tastes have largely diverged from classical art music, a good deal of "popular" (and often excellent, in my opinion) symphonic music is still being produced and listened to as film music and game music.