I’ve actually written a few papers on this area (not professional work but required a lot of research nonetheless) and a big part of why people think music is worse nowadays actually has more to do with the people. People tend to become mentally attached to music from their childhood and that music tends to compare favorably in their mind to newer music causing a very large unconscious bias whether we mean for it or not. Music is actually getting more and more creative every day. We just have way more music than we ever have and not everything is going to appeal to everyone. Music isn’t dead and there are just as many if not more talented musicians in the industry now than there have ever been.