I take it you haven't done any construction with a modern laser level? Have fun hanging level ceiling tile grid with your hose, hauling it around and keeping it filled between sites, making sure those walls are level horizontally AND vertically, and while you could use a hose/string for laying tile it's going to be much quicker and easier with a laser.

The only levels where you might have more than a couple buttons and need a manual are specialty ones like for surveying, not something you would do with a hose anyways.