You are probably thinking about "high culture" when you mention "culture". Culture is everything humans do to express themselves, from literature to theatre to entertainment to dancing to philosophy and religion.
Modern "culture" is almost entirely based on entertainment and pass time. How many times have I recommended a book and a movie to be told it's "too hard", "too serious", "not entertaining"... There is a reason why Marvel movies are always in the top of the charts, unplug your brain, grab you favorite sugary snacks and teleport yourself 3 hours in the future.
We call it "content" for a reason, shapeless and tasteless content to fill up the mere containers we became.
"High culture" is narrower, and of course there's the inevitable discussion of whether or not it is better. I'll note that one era's low or broad culture can become another's high (simple distance in space and time contributes heavily to this, with Shakespeare being a notable case). One of the strong functions of high culture is as a strong signaling / credible signaling device --- if you appreciate or participate in high culture, you're demonstrating that you've put in the time required to learn its nuances and backstory. This serves as an accessible indicator of attributes which are otherwise difficult to assess.
(This shows up in all kinds of cultural, faddish, or in-group behaviour, even in the name they go by, Shibboleths.)
Mass media has become a delivery system for advertising and propaganda (the latter has long been a function). Mass appeal means mass advertising markets, and explains much of the push for it. That said, "high culture" affords a cultural segmentation potentially identifying a more selective, and affluent, market segment --- one with stronger appeal to at least some advertisers.
The practice of adtech and interactively-targeted advertising ... somewhat subverts this relationship.