A solar tube is an odd thing to see in the wild. A skylight is obvious: it’s a big hole in your roof framed out like a window that lets sunlight pour in while excluding the rest of the great outdoors. Skylights tend to be large; several square feet or more. All that glass means a whole lot of free sunlight can come flooding in to light the room below.
A solar tube looks so small that it asks a question: How can a glass pane the size of a large dinner plate let in enough light to make it worth cutting a hole in your roof? And there is the fact the tube, which looks like an oversized dryer vent, ensures that the light has to travel a long way from your rooftop, through your attic, and thence into the room below. Surely light must be lost on the journey to the glass dinner plate set into your ceiling.
So the solar tube does seem questionable. They are expensive, need professional installation if you don’t want your roof to leak, and they don’t seem to offer nearly as much light as a skylight would.
In practice, they are tremendously useful.