Why should they pay tax without representation?

What proportion of 16 year olds are paying tax? My guess is <1%.

How many 16 year olds work enough to make above the minimum exemption? (£11,580) My guess is very few. Minimum wage for 16-18 year olds is £4.20/hr, but they'd need to make above £5.56 (11580/40/52) to have to pay income tax as they cannot work more than 40h a week.

I also assume the vast majority have no/negligible assets to earn income off.

So the only tax they would be paying is VAT, which everyone, including tourists, pay and shouldn't confer the right to representation.

Just as children are expected to pay maintenance for their parents when they are as adults in care homes, its reasonable to expect parents to pay maintenance for their children when they are getting educated. Its unrelated to being a adult. Besides that, you are right.

You're welcome. Glad to help.

You know that when you have to go to the extreme that you have lost the argument.