One of the main reasons is the need to present project development. The need to show the result not only to your clients, but also to investors.
Furthermore, I would certainly highlight the urge to record how the project was built and how individual project phases took place.
However, there might be some hidden reasons as well - a time-lapse video might be a by product. The Czech company Bixion provides solutions for time-lapse videos creation, enabling controlling individual project phases when it comes to building of the project, checking its alignment with deadlines and delivery of supplies, but also whether workplace safety rules are followed or whether suitable technology was chosen for production. The photographs can be used for marketing purposes - project presentation, thanks to immediate transfer of photos to online gallery. These particle activities would cost companies more money, this way it’s possible to solve multiple questions at once through creating time-lapse videos for the same amount of money.