I agree we're in the state of decline. Every nation in history has gone through or is going through the same cycle of ramping up, peaking, and then declining.
It's not just in the level of formal education people absorbed .... It's everywhere. I've always been into music and played in an alt-rock band for a while, back in the 1990's. I used to say there was no such thing as "bad music". It was all subjective and anything could be pleasing to the ears of the right listener. In recent years, I'd have to say that's still a fact -- but ... we're seeing a sharp increase in popular music that's mostly computer-generated or simplistic/repetitive, vs requiring a lot of musical skill. How many of today's rock songs actually incorporate complex guitar parts? How many have complicated drum riffs or musically interesting bass lines? Even with just the lyrics -- I'd say it's the exception, today, for a song to tell a full story or have deep meaning or clever lyrics. With your classic rock of the 60's and 70's, that was more of the norm.
The movie industry is the same way. Our local theater has such poor attendance for the latest Hollywood spew, they had to resort to showing random documentaries, which turn out to be far more interesting and draw in a more intelligent crowd, willing to pay the ticket prices.