A review of a human powered ornithopter that really worked shows how hard the problem would be for anything where a human was the main source of power. Even with an exoskeleton augmentation, the power in any affordable batteries would be too little & the weight of the batteries would make human power even less important.
Better results have been achieved by human powered propellers than ornithopters.
& technology hasn't really changed since then.
Now that someone has revived the idea, a lot of people are again going to be in a race to build the 1st human augmented ultralight. The trick is ultralights & gliders have been around forever. Electric ultralights have been around forever.
The human powered ornithopter that actually flew needed the biggest wing possible. It could only be flown in the deadest calm. It still needed a tow on the ground. It was hardly a recycled kite.
Surely many skinny unmarried men have already tried extending their flight time with human power only to find it negligible or the amount of battery mass required to augment the human eliminated any benefit of human augmentation.