(Possibly) Stupid question about school supplies

You know what’s coming: why do I need to buy 12 Dry Erase markers? Per kid, let’s say there’s 20 kids in the class – are 240 dry erase markers really necessary for a school year? 48 pencils per kid? Am I allowed to just send my kid to school with what they need? I’m so confused.

School supply shopping used to be my favorite as a kid because I got to pick out cool pens and pencils and notebooks but now I’m scared to send my kid to school with fun things because they probably won’t even see it again.

What do y’all do when that school supply list comes in? What’s common practice?

Edit: I appreciate everyone who gave insightful answers. I am not a teacher or in education in any capacity so I don’t know the normal use of supplies, etc. Our ISD isn’t the best communicator either so getting a response back before kids are back is hit or miss. I was still planning on getting everything but I wanted to know what exactly this was going toward because last year I saw a singular folder I purchased come home with my kid and nothing else.