Re: "zero marks for planning and foresight" - talk is cheap; implementing a Disaster Recovery plan is not.
I maintain two dozen or more open source projects.
All of them were started or inherited as part of my employee duties, but currently I am self-employed. While my previous employers were happy enough with the dissemination of their IP in open source - mostly to gain street cred useful to recruit the brighter young devs, I guess - they were much less inclined to pay for any CI/CD tooling and hosting.
Over time all the projects have been all migrated from Sourceforge, self-hosted svn, etc... to Github. Hard to resist a service that is free, well-known and loved by the oss community and has best-in-class features and ease of use.
What would happen if tomorrow Github goes titsup, or deletes my account for whatever reason? I surely do have backups of every project's source code, but it still would take time to upload them to a new hosting. Plus I would loose a lot of non-code project data such as open issues, web pages, lists of contributors.
The situation with Travis is not dissimilar: when it started it has a unique offer. Now it is not unique any more, and probably not free for long.
Will I be able to move to Giithub Actions? Surely yes. Am I looking forward to that with trepidation? Not really :-)