Yes it is exactly what we think is causing it. Students use LLMs to get 10/10 in assignments so they don't learn 'the thing' and they tank on the big-closed-books-non-LLM-exams.

BUT (apologies for the caps), back in the day we didn't have calculators and now we do. And perhaps the next phase in academia is "solve this problem with the LLM of your choice - you can only use the free versions of LLAMA vX.Y, ChatGTP vA.B, etc. - no paid subscriptions allowed" (in the same spirit that for some exams you can use the simple calculator and not the scientific one). Because if they don't do it, they (academia/universities) will lose/bleed out even more credibility/students/participation.

The world is changing. Some 'parts' are lagging. Academia is 5 years behind (companies paying them for projects help though), Politicians are 10-15 years behind (because the 'donors' (aka bribers) prefer a wild-wild-west for a few years before rights are protected. (Case and point writers/actors applying a lot of pressure when they realized that politicians won't do anything until cornered)