This billboard stood out when I saw it because rather than announcing that the apartment building was ready to move in, it said “almost finished”. It seemed funny at first, though I suppose the idea behind the marketing is to give the impression that this long awaited apartment building is about to be unveiled.
While you might not use 即將 in general conversation much, it’s still worth learning as you will see it in areas within the scope of daily use, such as the “coming soon” in a cinema:
In more everyday conversation you would say something along the lines of 快完了（kuài wánle） to say that something was almost ready. 快 usually means “quick”, but here means “almost”.