The real answer is the same reason younger generations grew up learning how to use excel and word and windows, a rich company found yet another way to acclimate users to their ecosystem and bypass all those pesky regulations around tech and kids[1]. They give out dirt cheap tech to schools to get buy in, they get data, users, (mostly for life, how many non stem people do you all know who explore things like the software landscape?), in short, like everything else, money is the answer. they get marketshare. Schools get to boast about their modernity. only ones losing are us 99%'rs.

[1] https://youtu.be/N3zU7sV4bJE