Vast development sites around Riyadh trumpet images of a shiny new future for Saudi Arabia—part of Crown Prince Mohammed bin Salman’s grandiose Vision 2030 agenda to turn the petrostate into an international hub of trade, technology and culture.Over the past year, the world’s largest oil exporter began pulling back on many of its promised projects and investments, met with budget shortfalls and unrealistic designs.Appeals for investment are sprinkled on ubiquitous construction fencing, along with English-language catchphrases such as “redefining livability” and “an extraordinary new normal.” Prince Mohammed’s vision extended to a pledge to invest up to $1 trillion in the…