I don't know if all of Andrea Bocelli's work count as opera because he tours performing his pieces instead of some operatic story but he's one of the best selling musicians in the entire world (>75 million albums). The article undersells just how popular he is.
If anyone has a chance to go hear him perform, it is a real treat. No other concert I've been to has sounded as good as he and the orchestra do live, especially Con Te Partiro (which he usually sings in the encore).
This article is just a "things were better in the good old days" opera remix.
Anyone who thinks you can't hear dramatic new opera singers who can project to fill a house and last night after night just hasn't been going to opera and listening with any sort of open mind
The paper talks about Verdi, Wagner, etc. The "Non piu andrai" link is Mozart, and not performed very well. In fact it supports the article.
For big spinto voices search for Franco Corelli, for big dramatic voices Mario del Monaco. And these two were already at the end of the golden age.
This is not a case of rose tinted glasses. It is all on YouTube and painfully evident. The article gives a couple of sane reasons: Very few people are exposed to singing in the first place these days, so talent goes unnoticed. The war on masculinity might play a role for men as well.
I think the specifics are correct but not confined to opera. I have no idea of how to convey the 'classical music culture' (if I could even define it) to "kids today" (ie., grandkids, who say "you listen to weird music"). That's with putting classical on the radio when I have them (captive!) in the car.
Interestingly, they do recognize clips (eg., Hall of the Mountain King) from various YouTubers stuff ("watch me play this game"), so it's not entirely out of the ecosystem.
Also, they are getting older, but ... the broadcast was 'Marriage of Figaro', I found myself bowdlerizing the plot: they're not quite ready to process the "right of seigneur". Most opera is PG!
The article suggests this is unique to opera, and classical music in general has not suffered as badly. I ran across this very interesting discussion today arguing that concert pianists of modern times measure very poorly with the greats of the early 20th century: https://www.youtube.com/watch?v=osdiIVaqg_M
If anyone has a chance to go hear him perform, it is a real treat. No other concert I've been to has sounded as good as he and the orchestra do live, especially Con Te Partiro (which he usually sings in the encore).