I think you are, at least to some extent, correct about the level of resources and that is certainly a vital evidential component in any claim under EC261.

This is certainly an area, if properly argued, where progress (as far as the consumer is concerned) could be made. If a claimant approaches such a case with a simple interpretation of 'extraordinary' (as in your car example above) it is bound to fail. Such cases could only succeed if proper attention is given to the 'reasonableness' test and a claimant can demonstrate the actions of the airline were unreasonable in all the circumstances and therefore inconsistent with EC261. If aircraft movements in and out are reduced then an airline will have no choice but to delay or cancel flights, especially so at an airfield operating at virtual capacity. The inconvenience is frustrating, but sometimes that cannot be avoided.

This is not an easy case to win and any suggestion to the contrary is folly. A claimant would need to advance some complicated legal arguments, with a detailed and reasoned exposition of current authorities and how, on the evidence, they apply/do not apply to the case before the court. I would say this task would be too difficult for someone without a high level of legal understanding or experience.