My parents kept tropical fish for many years, but they seemed to go through phases of dying, when some nasty bug got into a tank (even though we tried to quarantine them in other tanks). Also variously over the years; when we had babies, it was difficult to stop the other fish (including their Mum) from eating them, algae would grow on the tank, gravel, rocks etc which was a problem (I remember saucepans of gravel being boiled in the kitchen to clean it off! Smelly), Snails also took over a bit on occasions.
I found them OK to an extent, but I'd never have them myself, since to me the level of aggro involved seems to far outweigh the enjoyment.
My parents eventually got get up with them, and my brother took over, which was fine until one winter when he was away on holiday, and the undersoil heating in the greenhouse took out the entire house electrics. The tropical fish tank got a little chilly, which the fish don't like much. I think he gave up then, and didn't bother to replace them.