I'm not surprised that the ability to work from home makes people both happier and more productive. I have found the same thing to be true.
You have so much more control over your time and environment. If I can't focus on work, I can go do the dishes. This also makes it much easier to balance work, homestead, and spare time. Not to mention the time, money, and CO2 saved from cutting down on long commutes. Less lunch prep or temptation to eat out. Less interruptions during focused work. Less noise. Less of a lot of things.
Unfortunately it also means less socialising, as the text points out. Teamwork is more challenging, but it can be managed through regular calls and the understanding that you can always ping your colleagues in chat if you need help. There is also something to be said for not being forced into unwanted social situations. Not everyone gets along with their colleagues so some distance can actually be beneficial there as well.
I still remember what it was like to have psychosomatic illness due to the threat of having to go to school. My easiest year by far in university was during lock-down. And while I love my team at work, the word "teambuilding" still gives me the hibbie jibbies. Some measure of forced socialising benefits social development, but it is also very easy to have too much, and during adulthood I would argue the benefits diminish quickly.