I fail to see what the benefit could be in teaching a horse or pony a potentially dangerous manouvre just because it looks cute.
I expect, then, that you oppose show-jumping, for jumping is certainly a potentially dangerous - to both horse and rider - manoeuvre.
There is no 'benefit' in most things we teach our horses, or which we do with them. Horses in our world are animals used for entertainment and leisure - our own, or that of others - and so there is no absolute difference between, say, teaching a horse to jump, so that we may enjoy the sensation, or perhaps earn prize-money or even represent our country at major sporting events, and teaching a horse to shake hands, count or pull off its own numnah.
Jumping or 'tricks', any of them can be taught well, so that the chance of danger to the horse or its handler/rider is minimised, or taught badly in that such risks are not taken into account.
All my horses do tricks. So does my pet sheep, and the dogs. I trained the horses and the sheep, my husband trained the dogs. The ferrets do tricks, too - but they trained themselves!
What's the point? The same point as in training any 'pet' animal anything else - because it amuses us to do so.
Just to add: teaching a horse (or any animal) a trick that has the potential to become a 'vice' (rearing is one that springs to mind) is unwise only if the trainer is unclear about what they are doing and how to do it. Indeed, if an animal has already developed a behavioural problem/habit such as rearing, or in the case of a dog, excessive barking, then teaching them to perform this action on command is a well-recognised way of - eventually - eliminating the problem. If a horse is taught to rear, or a dog to bark, ONLY as a response to a specific cue, then you will reach a stage when the animal only rears or barks when given the cue. If you then phase out giving the cue, if the training has been done correctly and the problem was merely a behavioural issue, the unwanted behaviour will fade along with the cue-giving.