Hi there,
Industry knowledge is useful for brainstorming during the case. If you can’t think about the importance of the load factor in an airline case, or that customers may not pay for prescription drugs in some countries as they are refunded by the government in a healthcare case, you may be at a disadvantage compared to other candidates.
Having said that, you are not supposed to be an expert in any industry for generalist roles. Moreover, you should be able to derive the main insights with the right clarifying questions.
If you feel you are not strong in some industries (eg financial services, healthcare) try to do more cases in that sector – after 4-5 you should have a good understanding of the industry and be able to do better when brainstorming.
Best,
Francesco