What do working parents do when their kids become too old for daycare?

I'm just curious because I'm a SAHM and my mom always was too, so I know nothing about the stresses of finding childcare. If/when I eventually do go back to work, my husband and I can coordinate our schedules and I have my parents to help out, so I'm just wondering what do people who don't have options like that do when daycare is no longer an option? Where I'm from, daycare facilities, will not take children once they are 12, so do most 12+ kids just stay home alone for a little while before and after school? What about on school vacations and summer breaks? Do they stay home alone all day? What did/would you do with your kids when they became too old for daycare? Did you just trust them to stay alone for awhile? Did you worry about leaving them alone for awhile everyday or did you trust them to look after themselves? Did you ever encounter any issues with letting them stay home by themselves? I remember staying home alone for extended periods of time just fine When I was 12, but are most kids today okay to do that at that age? I could definitely see a typical 12 year old being okay to fend for themselves for a few hours before/after school, but are they usually capable of getting to school on time and getting things like homework done on their own? And are they okay to stay by themselves all day every day during the summer or do parents make other arrangements for them? Sorry for so many questions, I'm just curious as to how people deal with these things.