The question you have to ask is: If it's not you who has the best weapons, who is it? If it's not you devising military strategy, who is? The answer is someone else. Probably someone who likes those things more than you. Is that the sort of person you want to have that kind of power?
You're skipping the important part of the argument here, and going directly from the premise to your desired outcome without arguing why that will happen.
If what you describe were the unconditional outcome, how is it that our world is not gradually becoming more cruel and inhuman? I mean, there certainly are cruel and inhuman aspects to it, but for the most part, we live in a world that's vastly more prosperous and sophisticated than any other epoch before that, and also less violent. You included the link to Our World In Data yourself to prove that point.
Obviously, there are other aspects that contribute to the success of a society besides its military engagement. This can arguably be seen in how the influence of the US is slowly diminishing even though they have the largest military expenses by a wide margin.
Because not everyone makes the same naive choice to bury their head in the sand and say "moral people don't build weapons". There is a long tradition of great scientists making the only moral choice and choosing to develop weapons for the powers they trusted the most. Those people made the extremely hard, but ultimately correct choice to build weapons of war for imperfect powers. They did so because they knew that if they didn't, someone else would. And that someone else might be building them for an even less ethical power.
I think the key difference between our points of view is how strictly we want to define "being ethical". I'm pretty strict about the definition. At the same time, I'm okay with being labeled unethical from time to time.
It needs to be considered acceptable to tell your boss no on ethical grounds.
To make this concrete, we want there to be one bin for "putting live viral payloads in to vaccines destined for a foreign country," and another bin for "annoying shoppers with eye-level advertisements," and maybe another bin for "improving the efficiency of infrastructure." Ideally, irrespective of where the profit motives lied it would be impossible to recruit anybody for sufficiently nefarious purposes, with the recruitment difficulty scaling with how much harm they knew they were going to do to the world.
Something about supporting the military when it means resisting oppressive authoritarian hegemony, for instance, seems pretty ethical to me.