I've been doing the exact same with French for the past few years : you manage to find a lot of decent quality stuff in French overall, but as soon as you need to look up GitHub issues or stack overflow answers, using French is a clear issue.
Maybe the benefits are just too deeply hidden or there aren't enough benefits. Possibly there is a bias in search engines that enables the hiding of resources in other languages. (While they are quite persistent to offer me results in the language of the country I'm residing in, despite doing all my searches in English.)