There is a lot of truth to what you are saying. I do think the attention span of younger generations is getting shorter which is particularly bad when it comes to music. Everything is accessible instantly and it is easy to move on to the next thing if they are not instantly drawn into it. As you said, covers and remixes of familiar music does tend to draw more listeners than original music though there can be exceptions. Until recently, my most listened piece on my youtube channel was a brass quintet arrangement of a Star Wars theme that I did for my brother when he wanted it played at his wedding many years ago, so no surprised it got a lot of views and I admit, I have scattered a few other arrangements/covers within what is mostly original music to try to attract more viewer who then I hope will stick around to listen to my original music. And I think this does work; kind of out of the blue, an organ arrangement of one of my original choral works suddenly rocketed up to being my most viewed and is on the verge of being the most listened piece on my channel just within a couple years so I guess it is still possible sometimes to strike the right chord in people.