I'm concerned about all those things. The reasons I'm more concerned about AGI?
* Global warming is going to be painful, but seems like we're on a track that doesn't involve earth becoming completely uninhabitable. I'm still concerned about it.
* Companies have a much stronger incentive to make AGI than deadly weapons. It will be incredibly profitable.
* We have zero historical examples of a species developing a technology that is smarter than it is to look back at and establish some sort of probability for how this will go.
* All the issues with capitalism, where we have this system that isn't completely aligned with the well-being of humans, though it has kinda worked in the past -- now imagine that it's turned up to 1000 times the power. If you're worried about capitalism eating itself to the bone, that's the same thing to be worried about with AI.
To say that "producing words got a bit cheaper" really trivializes what a massive impact AGI will have, and how soon it's coming. I personally think that the probability of humanity being ruined or destroyed is probably either close to 0%, or close to 100%, and we don't know which, or if it's bad, how long we have. Even though 100% end seems more likely to me, I still think it's worth trying really hard to get to a good future.
If we had knowledge of this happening to several hundred different alien species, and could see the distribution of outcomes, it would be a lot easier to plan for this. In the absence of such evidence, I think it's a mistake to try to over-generalize from challenges humanity has successfully faced in the past, to "creating a new form of superior intelligence".