Charities should use direct debit not card details for regular donations but direct debits are much more expensive.

If they used direct debits you wouldn't need to update anything when you got a new card.

If these organisations had either the resources or the transaction volume they would/should switch to DD.

What you've experienced is the entry level option.

Charities have a skewed income distribution. Most charities are small with very limited resources, there is only for a relatively small number of big ones. So many probably do use the entry level option.

(I run a charity in the UK)