"writing “90 kBq” is a lot more convenient than “ninety thousand requests per second” and “90,000 requests/s”"

Not sure if article is serious or tongue-in-cheek, but no this isn't more convenient because it is more difficult to understand.

"requests/s" is best because it is the clearest, most unambiguous, and easiest to understand instantly. SI factors can be used on the number if needed (90k instead of 90,000)