Fight Flash Fraud (f3)
https://github.com/AltraMayor/f3
One could setup a destructive wear-test, but results may not be generalized between lots with identical model number. This is because some manufactures sell performant products for early reviews/shills, and eventually start cost-optimizing the identical product sku with degraded performance.
As annoying as the bait-and-switch trend became, for off-brand consumer hardware YMMV.
Good luck =)
I think it does practically the same thing as your method.
You can validate flash media with f3[1] on Linux/Mac or H2testw on Windows. These tools will fill up the drive with data, then verify that it all reads back properly. This ensures the drive meets the rated capacity and doubles as a sequential read/write test.
It fills the entire device with data and then tries to read it all back. It can tell you how many bytes were successfully read, how many were corrupted and how many were written over by other writes.
Even on cards I know are real I still run the test because I have had a card that had a few bytes that got corrupted which caused loads of issues with my rpi.