I agree we're having it easier physically but it doesn't mean we have it easier.
All desk workers are not knowledge workers. There are clerical jobs that are very different from what I call knowledge work.
Talk about working in a warehouse, I've worked in agriculture farms (manual, no machine forms) under open sky in India. So I'm not completely a stranger to physical work.
We might be not doing anything at all for 5 hours, on the other hand we're not really out of work. You can't shut off your work related questions whereas a warehouse worker can sign off and grab a beer and actually have a good time.
But I agree that there are some great benefits to be a knowledge worker because of better pay, better working conditions. It is better than hard physical labor but it doesn't mean it is easy.
This was written in a developer oriented blog, the title is meant to be a click-a-bait. So this is just broad generalization, there are a lot of people even in our industry working 60 hours a week and maintaining production systems, being on call, etc. I can assure you, though there are some benifits, we have our own problems.