But given the high levels of dysfunction/conflict that led to the breakup of the country, I doubt they'd meet whatever bar you set for "economic powerhouse".
Doesn't sound like Yugoslavia had a successful model.
PS. You're arguing with people who lived there. How can you be so certain you know better than those of us who saw it first hand? And I'm in no way saying it was a perfect system, btw.
You're using the past tense. Is that intended?