I think it can be fine if it's more of a marketing thing that I'm only going to view once and that doesn't have too much reading. Think of it like a promotional video that I can view at my own pace. But you have to have a good reason for it, cause there are lots of downsides.

And never use it for anything important, or that I might want to go back to multiple times.

This site is probably an example of a bad use case, cause it's the front page and I can't access the links without scrolling. Not to mention that it's broken on my device.