The Earth is mostly empty. Seriously. 7 billion people could all fit inside Texas - with a comfortable townhouse on about 33′ x 33′ of land for
each person. Most people live with families, so there would be realistically be even more space between houses and room for roads.
It's food production and infrastructure that take up the most 'space.' And this is not a problem of Earth being 'too small' but rather some 1st world countries consuming far more than they need and the human tendency to not want to spread out to less desirable locations.
(For example, about 5 gallons of water per person per day, to drink/bathe/wash is enough for comfortable and safe living. In the U.S. every person uses approx 80-100 gallons per day. That's enough to support 16-20 people. Or, consider that people in the U.S. throw out 200,000 tons of
edible food daily. A person needs about 3-5 pounds of food per day (less if younger) so 200,000 tons. Let's be generous and give everyone five pounds (whis is pretty high as it is almost a ton per year):
400000000/5 = 80000000
So U.S. throw away waste alone could feed 80 million people.
And while there are many crowded cities in the U.S. there is a lot of land which hasn't even been touched yet.
And then there is the fact that food production is not linear over time. Despite Malthus and others gloomily predicting overpopulation and famine due to linear food production and exponential population growth, in reality food production has well outpaced population growth.
Between 1900 and 2000, for example, the global population quadrupled (1.6 to 6.1 billion) but grain production quintupled (from 400 million to 1.9 billion tons.) Current population growth has slowed, but food production is still increasing and malnutrition decreasing as advances in infrastructure and production methods make food faster to grow, resistant to disease, etc. If food production increases follow this trend there should be plenty of food to go around.
https://theconversation.com/we-dont-need-to-double-world-food-production-by-2050-heres-why-74211
In the 1920s it was thought that a living density of 4,000 people within a square mile would be 'ridiculous' and put a cap on population growth - but many modern cities now house tens of thousands of people per square mile. Forecasts freaking out over population increases often forget to take into account human innovation and advancement. This is why God's blessing was not just to fill the Earth, but to subdue it and make the Earth work for us.