Almost everyone I know has been working 20-30% more than usual in the last year, are available basically at any/all times (and weekends), and getting the same salary. Plus, we're paying for the electricity of our work laptops now, and fridge, microwave oven, etc. Plus, no more paying for expensive company trips and meetings in expensive hotels. The fact that you can hire basically anyone, anywhere, means more competition and more pressure on the employee to work more and expect less from the employer.
This is one of the only comments I've seen that so perfectly captures the raw deal WFH will actually end up being for most people. Also, salaries will go down, not up, as employers pressure employees to move to lower cost of areas or emphasize hiring in those areas.
In a lot of ways I dream of a job I could well and truly leave at the office.
Why the hell would they open up again?