IMO, most engineers massively under-estimate the time it takes to do "simple" tasks if you don't already have the infrastructure/environment set up for it.
And some times they assume specific or latest versions of some platform because they are currently working on it.
I remember some flink take home required some latest api, while i have worked with flink in earlier versions. It took me 4h just to go through the updated documentation, while it was supposed to be an 1h one.