You seem to be assuming that bicycles get dirty in some special way that requires NASA to be involved in cleaning them; they get a bit muddy and a bit greasy/oily in certain places, and the above household cleaners are perfectly adequate to deal with this.
Yes, but like anything you can make a tailored product to work better for a specific area. Fairy cleans dishes, but I wouldn’t clean my car with it due to the salt. Similarly, a hairdresser once advised me that washing-up liquid and shampoo are incredibly similar, but I can’t imagine L’oreal doing wonders while cleaning my drivetrain. Apart from maybe coating it in wash n’go teflon.
You can clean your bike using WD40 as it’s a solvent and water-dispersant which shifts grime wonderfully, but there’s no way that’s going near my brake rotors. Or my hair, come to that.
Horses for courses – there are items in this world that are fuelled by marketing hype, but legally there has to be some benefit to any ‘advance’ that a company shouts about, and the laws on this are very strict. Consequently I would use a bike specific cleaner because the chances are that it has been tailored to work with the delicate plastics and carbon fibre on my bike, that Fairy may not like. You may see that as stupid, but I’ve invested significant funds in my bike and wish to look after it – to me that’s worth a few quid for some pink squirty stuff to use with the Dirtworker.