I would expect orders of magnitude more work done on ~20W.
Also parsing a compressed 10MB JSON seems like an unusual request. It would maybe be more fun to put a Hello World or Pet Store and get some numbers that will be more relatable to a regular developer.
On the other hand you can find a lot of benchmarks that use basically Hello World just to test your request response or some rather small request/response sizes, because this is what most applications actually do. You can add a simple database query to it for more realistic load.
So, yes, this is more relatable to me as a backend developer because I can compare results more easily.
I very much routinely look at large data sets. They just happen to be wrapped up in a different container than ZIP. Typically, they are delivered in MOV, MP4, WAV, etc. I look at a 10MB file and try to remember the last time I counted that small.
If you want to test CPU load, the author should have tried Prime95 or some other similar test.
Inefficient but not unrealistic outside of FAANG.