Realistically, the Moon would likely carry a mix of science, mining, and power installations.

Science - You can set up a large telescope on the far side of the Moon which won’t have an atmosphere to compete with. There are some concepts which would use existing craters to keep the cost low.

Mining - It is possible for there to be rare earth minerals on the Moon. There is also Helium-3 in the regolith. A country may choose to have a colony on the Moon address terrestrial shortages.

Power - The Moon makes an excellent site to collect solar power. That power could possibly be beamed/reflected to Earth, used to refine high electrical demand materials, or be a site for compute.

As this gets built out, the Moon will likely become a manufacturing hub, especially for missions beyond the Earth-Moon gravity well due to lower launch costs.