Canva and two of its longest-standing Australian backers have wiped $US7.1 billion ($10 billion) from the design software giant’s valuation as it struggles to find its feet in the artificial intelligence era.The downgrades from Blackbird Ventures and Airtree are surpassed by an internal valuation cut by Canva, and come a week after the company cut revenue growth expectations after finding it difficult to roll out AI-powered tools given the soaring cost of using frontier models.Subscribe to gift ...