As a candidate, I wondered why I didn't get detailed feedback on why I didn't get a role - now I'm on the other side, it often comes down to:
- Time and volume: think of how many applicants they've been through and the time it would take to write this feedback for each of them
- A good chance that people will dispute the reasons, leading to more time, more effort and more chance of a lawsuit
If it's at the final or penultimate stage, I've known this to happen. I also find it more common coming through a recruiter (as the company will be speaking to the recruiter anyway and knows that they will shut down any disputes you have).
As long as there's a concrete rejection email rather than never hearing back, that's all you should expect.
I can't think of an item I've bought from a store that was Shopify branded, but I know that a lot of big retailers online are using Shopify behind the scenes - Huel are, I believe Gymshark are - so unless you use Amazon exclusively (also entirely possible!), there's every chance you have used Shopify without knowing
I'll tell you about step 2 once I figure out how to do step 1