If you're not tied to anything in particular and can do a well paid job for a few years or longer somewhere else, there is no reason not to do that. You can at least apply and see where it goes.
Regarding ethics, I would say it's very very hard to avoid all unethical things you contribute to, so you shouldn't think that working or not working at an arms manufacturer or in a related field isn't contributing to some statistical death somewhere, even in devops, even if you were just a janitor. You can negotiate hard so at least it's expensive for them.
At the end of the day, those companies will continue to operate, because of political reasons. I don't think it's hypocritical to take a job at such a company and at the same time to be active politically to "tip the scale" in the other direction. You can support making weapons, but oppose using them. But you really have to oppose it.
...at least work for an industry I don’t think is evil.
You will honestly struggle to find one. That's not how the system works. Companies exist to provide a service, yes, but also to drive up the price and profit at any means available to them. In very rare circumstances, some companies will try to explicitly avoid this and do "fair trade". But even those and especially everyone else ties back into the bigger economic context, where "evil" is done by some company and not being stopped by everyone else.
It's a marathon. Do things that let you sleep at night. Do little good things where you can, if you feel strongly about a particular issue, connect with a community that is active in that area. Or you can just donate.
I've come to the conclusion that the best way to stop truly evil things, is to stop them politically. Not necessarily because it's the easiest way, but instead because it's the only to achieve a really effective solution. You or a group can only do so much, but if there is a law, suddenly a lot of people start to care about the topic.