The medical and veterinary professions would be unable to sustain a 21 hr work week. The only way you can do that and still service people's 24/7 needs for medical care is to have practices and hospitals with A LOT OF STAFF. And if all those staff are getting paid the salaries being paid when there was half the number of staff...well...

You think health care costs a lot now.

And that's just one example! And, regardless, the fact is that business and other services aren't going to be open and available any less. That just means hiring more people to fill in shifts.