This is an aerodynamic effect, but only one of many things that provide the forces on an aircraft. A pilot that neglects to flare will slam into the tarmac - ground effect isn't going to stop you. And saying that any floating effect you feel is directly/solely due to ground effect is way oversimplifying the many parameters.

Plenty of small-scale Wing in Ground Effect aircraft have been built - https://www.youtube.com/watch?v=svvfzETPmNg - and there have been proposed large scale adoption for aircraft the size of today's jets, though I don't see it happening.