Elementary school age kids don't drink hot tea usually. Maybe in England, but that seems like providing kettles for all the kids might be a bit of a burn hazard.
Then they can take themselves to a cafe and buy a tea or coffee. This is about what all the schools are permitted to serve the students. Yes, some are 17 or 18, and some are 5 or 6 years old. Sugar and caffeine are the two most addictive substances widely available to children, and few things manufactured are as profitable as caffeinated sugar water. Put it in a bottle with fancy colors and a cool logo, have some social media influencers plug the drink, and then find a captive audience that's sleep deprived, facing extreme pressure to perform, and too young and impulsive to make long-term healthy decisions. That's called a business model.
I'm not suggesting we start carding everyone who buys a soda, but schools are a controlled environment. Just don't sell caffeinated beverages at the schools.
This is the way. My caffeine habit started in middle school because I was needing to be up stupid early for the bus, missing breakfast, and passing out halfway through first period.