Not ideal for digital download variants

For me, the usability is low because the digital download product variants systems is clunky, requiring training and the implementation of third party apps, which seems suboptimal in my experience. I found this to be a no-go for long-term usage. For selling physical products or ones not demanding variants I think Shopify would be a choice on par with, say, Squarespace and superior to Wix.

It completely depends on the product they might be selling. If they are selling services or physical products, then Shopify might be recommended. However, if they are selling digital products, like me, specifically products that have variants, also like me, I would not recommend them because the interface and require plug-ins are suboptimal for these purposes.