Yeah, it's pretty common to have leases on land. Typically, a company might enter into such an arrangement. It's not that big a deal. It's just another cost that gets built into the cost calculations when trying to figure out if it's worth it to be profitable. There's new construction all the time, so at some level, building new buildings is profitable.
The builder could use the newly constructed building or sell it off. With a land lease in place, the selling price might vary from a sale where the land is sold with the building.
When the lease ends, there are a few options. The company could renew the lease and keep going if they work that out. Otherwise, all the stuff on the land goes back to the owner. The company has the option to demolish the building and it may even be required to do that once the lease is up (kind of like how you're supposed to leave your apartment about the same way it was when you got there). So, the next guy has a clean slate and can build whatever on the land again. Alternatively, the owner of the land could buy the building from the company when the lease is nearing the end as another possibility to prevent the demolition.