I often worked from home long before Covid, and was able to manage my time to ensure that I was there for students when they needed me, could attend meetings (before Zoom or Teams were around) give lectures and so on. I found it more efficient, however, to do a lot of admin and research from home. When I work now, it is 100% from home, using Zoom and logging into the University system to access documents and upload my own. At home I might have put a load of washing in, or collected the children from school, but I wasn't constantly interrupted by colleagues, phone calls and students 'dropping in' with queries that could be answered by email. If someone needed to see me, they could leave a message on email and I would get back to them by telephone, or arrange a face to face meeting the next day. I was always very contactable, but I didn't need to be on the premises every day to achieve that.
With suitable management, there is no reason why flexibility should lead to inefficiency. If people know that they are expected to meet targets and will be answerable if they fail, why does it matter if they are doing admin at 4.00 when the children get in, or at 9.00pm when they are in bed? It seems perverse to insist that tasks are completed at a time when it is most inconvenient, instead of when they can be fitted around family life. What is sacred about the nine to five?
I am pleased that more people now have the opportunity to WFH (it was quite unusual when I did it in the 90s). We so often hear about how children need mothers at home, but when those mothers (or fathers) try to arrange things so they can have quality time with their families they are castigated - often by the very people who also complain about both working parents and benefit claimants. Just what are parents meant to do? If they work they are wrong. If they claim benefits they are scroungers. If they work and also try to be there outside of school time they are 'annoying'. It does look like they are being set up to fail.
As for mental health issues - people are all different. What might be stressful for me (so bad for my MH) could be something that others thrive on. Nobody can decide what others should do for the best where that is concerned. Galaxy has said that commuting is stressful for her. I don't work well in a busy office with lots of distractions. A friend of mine prefers noise to silence. Probably most parents will work better if they know that they can go to the Nativity play and to parents' evenings, and if they have the sort of job that can be flexible, why on earth is that a bad thing?
The ability to log into a work IT system was a game changer. I wonder whether those who criticise WFH have ever used that facility and understand that it makes absolutely no difference whether something is recorded onto a system from an office or a kitchen table, or between 9 and 5 or later in the evening.
Some people have jobs that don't lend themselves to WFH, but that shouldn't stop the rest of us from doing so where appropriate.