Google Search enjoys multiple economies of scale. To list several:

1. Data about what the population is interested: More people use Google today, giving Google more data to train its AI with.

2. Server capacity: It's cheaper for Google to store 1 image than for me to store 1 image, because it stores many more images. Same for compute, such as training AI. Google can get one A100 GPU cheaper than I can.

3. Ads: If I had the exact same search quality and even the exact same number of users, Google will make more money from the same operation, because it has more advertisers.

They set up their business well!