I always think of a Dilbert from the mid 90s along the lines of “when working from home, do I owe the company 8 hours of productive work, or just the same 2 hours of productive work I’d do if I were in the office?”
in theory, the same 2 hours - but you need to be available the whole 8 hours as if you were sitting in the office.
No. But there's generally a difference between what people can get off with at home and what they can routinely get off with in an office.
Does the company really care about whether they are vacuuming their floor or browsing hacker news?
Vacuuming is more restorative than hacker news. Gives your brain a break and gets you off the computer
At home people probably play games or watch netflix instead of just browsing forums, I don't see people do that a lot at work, and I can see that reducing productivity more than just browsing forums.