Mandelbrot's analysis is certainly the more dynamical. I would add that the institutional structure defines the parameters for macroeconomic development, regardless. The existing system can be improved in such a way that the economy would become self-regulating, more just, and more environmentally viable--yet retain its dynamism, its inherent capacity for self-development (mostly through technological innovations, which would still be highly materially rewarded).

If curious, "A Most Beneficial Economic Change" is a "2 min read" here in Medium with links to more essays about the proposal from different angles (with nothing I publish here behind the paywall).