“The practical value of the censorship resistance guarantee is dependent on (i) L1 fees being sufficiently low, and (ii) L1 having enough space that users can send bypass transactions even if an L2 censors a large number of users en masse,” he said.
Buterin also gives the example of an L2 mass exit situation, saying that at present, Ethereum might not be able to handle a mass withdrawal if a large L2 with millions of users collapses without scaling as much as 9x.
He outlines several other potential scenarios before concluding that “there is significant value to ~10x scaling of L1 gas even in an L2-dominated world.”