what is wrong in having Under 16s, Under 19s and Under 23s (or 'A' team)

nothing but 75% of the teams will reject that due to the expense.

But it wont cost ewt in wages because all the players are already capped paid!
The boundaries of a clubs enterprise is all that hold back how profitable it could be!!

I would defo be a regular if it was priced at a fiver and kids free to a £1!
When inside its all about how much crisps pop pies hotdogs and pizzas they can sell.
That's were profit can be made.

The U23 and U18s players would all be on a salary, bare minimum agreed £3k at the youngest age group. The U16s don't get paid but they still have kit, transport, nutrition and backroom staff support. Considering most clubs run at a loss this is hardly insignificant.