I think its farcical to claim that a 4 day week is a 'scam' because you find it offensive for whatever reason. Its still an improvement on the 5 day week and something atypical. I am not sure what you think a 'scam' is but we have different definitions.

The number of people who are working from home will not be 100% nor will the number of companies working from home exclusively be 100%.

Given we have had limited time to run this experiment, perhaps it would be good if we didn't just jump to conclusions that working from home is the be all and end all. The office has had a pretty good run of productivity over the last century.