There is no additional security to be gained by a random megacorp that has leaks every other month "attesting" that I can use my things well.

And Google didn't add attestation to make sure my bank details are safe, it did it as part of a concerted effort from the industry to make sure I am not able to make my computer work as I want it to work and run code I want it to run. Google does not care about bank fraud as long as it doesn't affect its stock price.