I can understand teachers probably want to minimize complaints from parents. You probably don’t want to wear your finest clothes while fingerprinting or making crappy crafts.
So I can see wearing, say, an unliked T-shirt. But I have vague memories that some of our classes had access to yellow smocks of uncertain hygiene.
It’s not like we were decorating the Sistine Chapel ceiling or changing the colour of the Oldsmobile. So what was up with the smocks? Did you have those too?
It has the advantage of being fun to say. Smock. Smock. Smock! But necessary?
I came home on my first day of kindergarten (or in the first week, anyway) with instructions that my parents needed to send a smock into school with me before we had our first art (fingerpainting) class. My mother made one for me (out of an old shirt, probably). It is a fun word - I enjoyed learning it (in contrast to my disappointment when I learned that the kindergarten did not have a laboratory (as I was sure the teacher said) - it just had a lavatory)
We had to wear smocks in kindergarten (we brought our own). I remember some kids wearing their dads’ shirts, but I wore a kid’s full apron. It was blue with a big red apple on it. I can picture to this day.
I don’t remember wearing a smock, but I do remember in 3rd grade complaining about learning Art when things like Science, Reading, and Math were much more important. Poor Mrs George!