The pantos you remember from your idealised childhood were local productions.
Many of them were produced by locally owned and managed theatres or by municipal theatres funded by local authorities.
They organised into corporate groups to achieve economies of scale.
These theatres cut back on producing and became touring houses.
Each panto is created and cast to a national pattern. The same as happened with regional commercial radio.
Panto = standard script, a local DJ, one or two soap actors, etc
It's neoliberal capitalism producing what it does best: a standard product at scale, at the minimum quality level the market will tolerate.
The kindest way of describing her is a Poundland demagogue.
But if anyone ruined the traditional panto she claims to love, it was her own party's policies.