I think so, but note that the NPR piece you linked to is based on obsolete pre-Delta data in the United States and by all accounts hospitals are seeing more sick kids than they did last year (some combination of known greater virulence and what the CDC classes as probable greater severity).

The best argument for treating COVID more seriously is that we have a better understanding of influenza’s long-term effects. In both cases, however, I’d argue that it makes sense to require vaccination simply to reduce the impact on childcare and education: even if dying from the flu is relatively low-risk, it’s stressful and disruptive when it rips through a class and vaccination is quite cheap in comparison.

There are a few vaccines I had to have for school when I was younger. What’s the difference?

Compare the severity of those viruses in children to Covid.

A more apt comparison is Covid to Influenza. You don't need flu shots to attend school.

You're legally an adult, you have full legal control over your body, you're legally fully responsible for your choices, and you're not in school any longer.

You mean other than that?