They are called teachers because they teach you how to use stuff, sometimes ABCs and 123s. I was a daycare teacher in a way, with my high school diploma, i was a newly graduate and my ex mother in law got me the job (unfortunately after breaking up with her cheating son of hers, she got rid of me too but whatever)
I was called a Teacher because we used to teach our kids how to be independent, teach kids how to respect everything and everyone, teach them how to plant plants and give them health to grow (responsibility) etc etc, we would have "lessons" (in other words, class work) that would teach kids how to color, put puzzles together. During some time, while the assistance used to change diapers, one teacher would stay with the kids pronouncing and teaching the kids the alphabets and numbers. And after that it was recess, and after that it was singing time with friends, then some students either goes home at 12:30pm or stays behind and eat "lunch" after lunch we check diapers again and put them to sleep until 2pm when school is over.
It's almost close to being in 1st grade.
So yes, you do need a teaching degree to be a teacher and TEACH but in my case, i was working within family and i was an exception because my career path is to be a teacher and that work will give my resume a good boost when applying for a teaching.
I hope i helped!! if so, please vote for me!! <3! thank you!