Infrastructure costs for a project like openwrt could be nearly zero if the infrastructure was designed with cost in mind (site behind cloudflare, free tier in Aws/Google cloud for build bots, code on GitHub, etc).
You can probably run the whole thing for $100/year of unavoidable costs (eg. Domain registration).
Also did CI/CD on OSS projects and highly agree with this - CI/CD is not free, especially if it involves anything hardware related, which is likely in at least some subset of OpenWRT's cases.
You can probably run the whole thing for $100/year of unavoidable costs (eg. Domain registration).