There have been and are some good tree stands on the market. But no tree stand is perfect. Hunters are different, very different.

A tree stand might be great for a 25 year old, and not so good for the 40 year old.
Some hunters can put their backside on a 18 or 19 inch seat; for others it would be a physical impossibility.
Some hunters are fit to carry a 20 lb. tree stand, a rifle or bow and a small backpack a thousand yards. Some might have a bad back or are so out of shape, crossing the back yard, with that load, would be impossible.

Some hunters have a real fear of heights and would be uncomfortable at a height where they would look on the stand as a postage size conveyance. Advertising doesn't get into that.
Some are more comfortable with a bar across the seat and front. For some, some tree stands look as open as high dive swimming platforms. Great for some to perform their swan dive.

Some tree stands are too small and tiny for some hunters; as some tree stands are too big and heavy. And if you're over 300 pounds someone has a tree stand for you. You don't need a doctor's permission.

And paratrooper harnesses. And a mountaineering rope, so you can repel from atop a tree. And everybody knows all tree climbing hunters are fit to do ten or twenty push ups easily.