That's just your avg elitism. The idea that the world is better by making the creation of art expensive so that only a small group of elite people is nonsense.
Effort of course went down that's clearly a good thing. As for quality, before you needed to get enough return to pay for the expensive equipment and process, so likely you only do it for very few project. So on some abstract sense maybe 'quality' did go down, but that isn't bad as the total amount of high quality goes up far more.
See the massive amount of great TV that have happened since digital cameras.
> slop
What's slop for you is somebody else's favorite show.
Art doesn't have to 'impact us in a positive way' whatever that means. You are not a better person for having watched "Lawrence of Arabia". And in the past most people didn't watch "Lawrence of Arabia" but generic TV shows.
Personally I can easily filter the 'slop' (ie thinks I don't care about) so given how much better the ability is to select what to watch. On demand media libraries, recommendation systems, digital word of mouth and so on. In the past there were few TV channels and only a few movies in theaters at the same time.
So the total access to high quality content has gone up exponentially.