So you're just being pedantic, but also wrong. Britain was never technically an Empire, only the United Kingdom was. The United kingdom might as well be a republic, since functionally speaking there is no difference between representative democracies and parliamentary democracies. The main point being they are both democracies and being pedantic does nothing make make you look worse. The final French Empire stopped existing in 1870 after its defeat to Prussia, and only Prussia. They retained a vast array of nations and colonies until the 1960's, same as the United Kingdom. The Netherlands are also a Republic.

And you're accusing someone else of not reading history?