Nothing to do with waking up.

But it's something I find to be a pain, so now when I have a multi-day booking and am unsure of whether I need the last day or not, I just book a separate reservation for that day; with AAA or BFRs, that last day can usually be cancelled by 6 pm that day, thus avoiding the "early departure" nonsense.

Another benefit of splitting reservations is that for rates that depend on being booked 3 or 7 or 14 days in advance, your second reservation is often at a lower rate THAT YOU DO NOT GET otherwise.

Let's say there is a hotel where the >14 day rate is $200 and the <14 day advance rate is $240. The rate is based on your date of check in. So if you are reserving for 4 days and it's 13 days in advance, you would get 4 days at $240. On the other hand if you split into 2 and 2, you would get the first 2 days at $240 and the second 2 at $200. And you can cancel that second reservation if you have to, rather than pay "early departure"

That said, while I have had hotels enforce the no-show cancellation fees, I have yet to find one with the temerity to charge me an "early departure" fee. But I am a good camper and if my departure is flexible/uncertain, I advise the hotel in advance.