I would agree wholeheartedly with this. Certainly when I was younger during the 60s and 70s the record companies were making huge numbers of classical albums the CDs of which we see in charity stores today. But there was also classical music on the television for the general public with things like André Previn‘s music night, at a time when the BBC in Britain were actually interested in promoting culture rather than chasing ratings. They are actually re-broadcasting some of these programs at the moment so there might be a glimmer of light in the darkness that the present bunch in charge are waking up.I voted 1950 -- the year I was born -- but can tell you the peak of classical music in my lifetime occurred after that probably between 1965-90. I chose the end date because that's the year Bernstein died, a year after Karajan died. When those two were alive the world of classical music was much different than today. The biggest difference is it was far more represented on TV and in popular culture than today. I saw Karajan conduct opera on Public Broadcasting, PBS also once broadcast an entire Ring cycle on American TV on four consecutive nights, and Bernstein famously led the Young People's Concerts on American TV. In the early days of cable TV through 1990 channels like A&E and Ovation regularly scheduled classical music programming.
Today, in the Internet dominated world of the 21st century, this is all gone. PBS may program a little classical music but virtually no other TV channel does so. I know the world has gone to streaming and perhaps there are streamed outlets people turn to. But if so people do not turn to them in large numbers.
I think Bernstein and Karajan were the last "name brands" you might say that existed for classical music. The only things of consequence that have arrived since them was the period performance practice movement -- which the average listener doesn't give a hoot about -- and the The Three Tenors, a big hit in the early 1990s. The only worldwide musical hits since then have been Gorecki's Symphony of Sorrowful Songs, Adams' Doctor Atomic opera, and ... what else? It's hard for me to name a single person active in classical music a person that likes music might know. Just about everyone knew James Galway in his heyday.
I think the irony of today's reality is so great because, as classical music has declined from what might be called public view, there is more of it around the world, played better, and millions more classical music lovers. Today even a local orchestra made up of students and retirees who pay to play are good enough to schedule a Mozart or Mendelssohn symphony. I read in a classical music journal yesterday a review of a Mahler recording by the Grand Rapids (Mich.) Symphony Orchestra so good the reviewer favorably compared it to historic recordings by big name European orchestras.
We live in a world where standards and practices are better than ever before everywhere but ironically in a world when the art form itself has disappeared from public view, in my opinion because there are no longer living composers whose work is so great it creates new fans overnight. Today, if you're not a fan of classical music and don't seek it out, it's not coming to find you. That is a big difference in the world in 2022 compared to the world I knew decades ago.