If everyone ate as much meat, dairy, etc. as many industrialized countries do, there would be no land left. If everyone ate like Americans, we would need 137% of the world's habitable land which includes forests, urban areas, arable and non-arable land, etc. Cutting down every forest wouldn't even be enough

Source: https://ourworldindata.org/grapher/share-of-global-habitable-land-needed-for-agriculture-if-everyone-had-the-diet-of