Why did navies avoid building every carrier at the maximum size?

Why did navies not build larger carriers with both armour and large hangars?

They needed more carriers than the cumulative treaty tonnage allowed at maximum size. A 135,000-ton allocation accommodated only five 27,000-ton carriers, forcing a trade-off between individual capability and fleet numbers.

The individual ship limit allowed a 27,000-ton carrier with armour and substantial hangar capacity. The cumulative ceiling then restricted how many such ships a navy could operate. The 135,000-ton American and British allocations allowed only five carriers at that size, while Japan's smaller allocation allowed fewer. Fleet numbers therefore forced compromises in the size and protection of each carrier.