So what is honestly the point of them now. Like, They are easilly pissed off, no good items to trade, and not good at combat. Is the only reason we have them in the game to has some one to hate durring the off season that we don't have any goblins to hate.
Pretty much. Elf slaughter is the favorite dwarven pastime!
Now... if you settle in an woodless embark you probably will want to keep elves around. You can buy wooden barrels, crutches, buckets, splints, etc from them. I don't believe I've seen them bring BEDS, but they can bring logs.
Some people like to rely on caravans for their cloth. Skipping right to the cloth removes the steps of growing/spinning/weaving the plant fibers (or breeding/shearing/spinning/weaving the yarn). So the more cloth you can outright buy, the less you have to crank out yourself. Elven clothing is also of the same size as dorfs, so you can buy their hippie rope reed vests and hemp trousers.
The same is true of food- some people like to buy out caravan food to toss in the larder. Food is far too easy to make in abundance on even tundra maps though... so *shrugs*. The final answer lies in the exotic animals they bring. Sometimes you get some cool animals to breed.
If nothing else, gauge what biome they are from on the first two caravans so you can gauge what animals they might can bring. I've seen them bring grizzly bears and other in-demand animals (WAR GRIZZLIES RAWR!!!!) One fort got me a breeding pair, so I decided the elves could live for the rest of hte fort. Others buy out lots of cloth for the first few caravans then slaughter them. Others just straight to the dickery and seize the entire elven caravan's stock of goods from the first visit.