I don't know about about the breeding or farming aspect, but yes, kittens can be hard work. Some are more trouble free, others a menace, albeit a very cute and adorable one, that they usually grow out of most of the challenging behaviours. I foster for a rescue charity, so have had dozens of kittens come and go over the years.
But if you're looking at a kitten under about 4/5 months, please get a pair. If you only want one cat, get an older one as kittens learn so much about being a cat from playing with siblings at 2/3/4 months of age, plus they're still babies so benefit from the comfort of someone to cuddle up to. If you look at breed rescue, you might find an older kitten that's had to be given up due to allergies or changes in circumstances of the owners.
With an older cat, you'll miss out on the 'tiny cutsy baby kitten' stage, but that only lasts a couple of months anyway.
But you'll also miss out on them going to the toilet in various hidden places like behind the curtains, under the bed etc while they get to grips with litter trays. Or shitting all over the place because their delicate tiny baby tummies have decided to disagree with the food that you've been successfully feeding them for weeks. Or pissing in the nice, expensive, non washable bed you just bought them.
The last two I had damaged my quite expensive new curtains by climbing up them constantly. Kittens also often climb up your legs when you're preparing their food, leading to ruined clothes and painful scratches. We've had some so persistent at that, that it's been necessary to box them up until it's ready.
We've had them that chewed wires, thankfully only phone chargers not mains voltage.
Run round all night noisily, play with the noisy toys while you're on teleconferences, if you shut them out of the room, they cry and scratch to be let in. Like to sleep on your bed at night, but then insist on playing at 4 am. But cry and scratch outside the room if you shut them out.
Horrible beasts, we haven't got any right now and I miss them terribly
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