Docker Swarm isn't Docker; it's an orchestration service on top of Docker, that happens to have originated with the same organization that Docker does - hence the name. A few years ago Swarm looked like it might be competitive in the container orchestration space, but then Kubernetes got easy to use even for the small deployments Swarm also targeted, and Swarm has withered since. It wouldn't be impossible or probably even all that difficult to switch over to k8s if that were the only blocker, but as the sunset post notes and you here ignore, that wasn't the only or the worst problem facing SSLping - as, again, the sunset post notes to your apparent disinterest, it's been losing money for quite a while before it fell apart.
(Has it occurred to you that it losing money for a while might have contributed to its eventual unmaintainability, as the dev opted sensibly to work on more sustainably remunerative projects? If so, why ignore it? If not, why not?)
Similarly for the Node aspect - that's very much a corner use case related to this specific application (normally SSLv3 support is something you actively don't want!), and not something that can fairly be generalized into an indictment of Node overall. Not that it's a surprise to see anyone unjustly indict Node on the basis of an unsupportable generalization from a corner case! But that it's unsurprising constitutes no excuse.
Other than that you seem here to rely on truisms, with no apparent effort to demonstrate how they apply in the context of the argument at which you gesture. And even the truisms are misapplied! Avoiding dependencies for the sake of avoiding dependencies produces unmaintainable software because you and your team are responsible for every aspect of everything, and that can work for a team of Adderall-chomping geniuses, but also only works for a team of Adderall-chomping geniuses. Good for you if you can arrange that, but it's quite absurd to imagine that generalizes or scales.