I worked for one of these useless company in the past and it makes me feel terrible at the end of the day. Now that I have a bit of money saved up, I don't really mind to get payed less.
Find companies you think are doing something useful and reach out on LinkedIn directly to relevant team leads with a quick intro to you and why you are interested/potentially useful for them. Even if they don't have headcount they might know another team that could use you or a role that isn't advertised yet etc. Obviously be respectful and don't spam but I think most people aren't offended by doing this.
I feel like most of the dev (and other) jobs out there are just similar variations on how to extract value from someone. Maybe you write the code for Amazon's website - so what? So people can spend money on stuff they don't really need?
The point is, nobody here can tell you where to find a 'useful' job, or even what that might be to you.
Here are some good Golang developer jobs you might find useful.