This quote is talking about the status of the visual arts – things like painting and sculpture. It suggests that these kinds of art forms have been becoming less popular and important over the past 40 years, while performance genres like music, opera, theatre, and dance have been increasingly successful. The quote also notes that since the early 1970s, when Pop Art and Minimalism were popular, no major influential figures in the visual arts have been seen. So, this quote is suggesting that the future of the visual arts is uncertain and does not look very bright. In short, it is questioning whether art has a future.