The laws within the country by which the product operates - and stores data - might not be compatible with regulations in which the customer must operate. The legal headache for a US/EU company to use a SaaS product from China would not be worth the cost and risk. It's not about the company or teams trying to prove trustworthy.
This is the most objective answer! If a Chinese SaaS company wants to grow in US/EU, compliance is a place they must invest in.
Something along the lines of “We will grant you a license to operate in EU/US on the grounds we have full authority to inspect all customer data to ensure you are complying with CCP regulations”
Either way it’s a tough uphill battle for Chinese companies!