If you think water hasn't gotten a taste, you've clearly never been massively dehydrated.

Sugar takes a long time with a large quantity before it becomes harmful. It also offers a lot of benefits in the short term. So, if sugar had been abundant, it still would have been very important to humans. Humans didn't evolve the want for fat. We inherented it off the animals, who inherented it its ancestors and so on. So the want for sugar is just us following our biological need for us to have fat. So if sugar had been abundant, we'd still find it delicious because our biology wants us to be fat.

The evolutionary pressure to not eat sugar if it was abundant because of the damage it would do wouldn't be enough. For something to evolve, it had to disadvantage someone from breeding. Once something as an offspring, it's already passed on its genetics. If sugar was abundant, it would probably be the safest source to get. Back when humans first evolved, your only option was either to kill something that is dangerous or forge for rare berries, etc. Having an abundant source of food, even if it's bad for you, would massively increase your likelihood of survival if you ate it.

Think meat delicious despite the fact that it was relatively ubudant. Being one of our main food sources. It's still delicious because it is a great source of energy.

You've got to understand how evolution actually works to understand how things would affect it. Evolution isn't perfect. Evolution is just the effect of having small variations occur genetically, where if they are beneficial on how many offspring they have, then those genes spread. If it's not beneficial on how many offspring you have, then those genes dissappear. So, it can't take into account what happens after the creature has its offspring. Which is why we all die.