Shinzo Abe (RIP) implemented a bunch of daycare reforms as part of his "three arrows" campaign. These included massively reducing the cost as well as increasing investment into availability.
In just a few years it went from being so expensive it was not worth the mother working a part time job because that money would completely go to daycare to being 100% free until the kid turns 4. Availability also went from long waiting lists in most cities to now only having waiting lists in a small handful of districts (mostly in dense areas of Tokyo where just finding the room to build them is hard but also in my rural area where the salaries were so low all the daycare workers moved to higher salary areas and hiring was impossible).
So while it's not perfect it has gotten much much better in a relatively short time.
In just a few years it went from being so expensive it was not worth the mother working a part time job because that money would completely go to daycare to being 100% free until the kid turns 4. Availability also went from long waiting lists in most cities to now only having waiting lists in a small handful of districts (mostly in dense areas of Tokyo where just finding the room to build them is hard but also in my rural area where the salaries were so low all the daycare workers moved to higher salary areas and hiring was impossible).
So while it's not perfect it has gotten much much better in a relatively short time.