Large companies can’t. A company building a hospital, isn’t going to have another job lined up, to start the day the one ends. The first job probably won’t be done on time, now you have two jobs going and only the same amount of employees. The last part of building is always the biggest rush to finalize punchlists and everything.

Smaller companies, yeah they typically can operate that way.

The company also has to get paid for the first job, before they can have the equity to be able to even buy materials for the next job.