The reality is that ship sizes were limited by a number of factors

Often, the size of ships was limited by budgetary factors. There was also a strong British navy prejudice, at least in some quarters, against really large ships. In the "1921" design process, for example, they had to back off from 18in-armed battlecruisers and accept 16in guns. The battleships were still to be armed with 9-18in guns, but the battlecruisers had to have smaller. The battlecruisers were really fast battleships, but were only limited in armament, not armor or speed. They were really much better ships than the so-called fast battleships built in the late 1930's and early 1940's. The American ships were especially underwhelming. The worst were the North Carolina class. Their problems were partially corrected in the South Dakota class. At least, the South Dakota's were structually sounder and better protected.