Perspective from someone with a child (1.25 years old):
When my wife and I chose to have a kid, there was absolutely no reason to think that we would have any difficulty finding a nanny/daycare or that we would have to try to work in the same environment that our son is playing in. When COVID-19 restrictions went into effect, we had basically no notice that we would be expected to work from home full time, that our building's common areas would all be closed a few days later, that our nanny would be unable to make the commute (no license should not have been in issue in NYC) and that daycares would all be closed exactly when we needed to find one, etc. We had to move just to get an extra room that could be used as an "office," because working from the kitchen table is impossible when a baby wants to crawl up to you, pull himself into a standing position, and grab whatever you are "playing" with.
Even with the extra room, we still have trouble. Our son walks (and runs) now and is beginning to understand how doorknobs work, but he still has no concept of leaving us alone to do our work. If he has the chance to run into our office he will, and if he does not he sometimes bangs on the door and cries when nobody opens it. Either way it is a huge distraction that makes it much harder to get anything done. Try explaining to a toddler that mommy and daddy are working and see how far you get. We also continue to see chaos with our childcare arrangements, which takes its toll on productivity.
Your side hustle is optional and can be put on hold. When you already have kids you cannot stop being a parent and children cannot be paused. I agree that employers should give people time for "personal obligations," and in fact mine does and my boss has been using that time to check in on elderly parents, but the fact is that parenting is one of the few 24x7 personal obligations. It is not like I can say that I am setting aside one day a week or two hours per day to be a parent.
As hard as it is to deal with a toddler while trying to work, it is harder for parents who are being told that they must supervise their children's schoolwork. It is easy to forget that part of the job of a teacher is to watch over the kids in their classroom and ensure they are not just goofing off all day, but with kids doing "school from home" that is now the job of their parents. Again, it comes down to having someone else there to take on that job while parents are working, and again it is not a question of time and it is not something optional that people can put on hold until the crisis is over.
Basically there is no way to make any of this sustainable. COVID restrictions make childcare arrangements more difficult and less reliable, but those gaps must be filled and in the end it is parents who have to fill them (if someone else could do so, then it would not be a 'gap').