Colin Tudge says this:

“Indeed, whereas taxonomists once recognised just two kingdoms of eukaryotes (animals and plants) or three (animals, plants, and fungi), or four (animals, plants, fungi and ‘protoctists’), some modern biologists now acknowledge 20 kingdoms or more, and most of these are protists. Our own kingdom, the Animalia, has thus been dramatically demoted: from a conceptual 50 per cent of the whole to less than 5 per cent. Thus humans have been driven from the centre of the biological stage just as the astronomy of Copernicus and Galileo shifted planet Earth from the centre of the Universe.”

Colin Tudge, The Variety of Life, Oxford: OUP, 2000, p.128