I have nothing to add other than Jekyll has been rock solid for me for, what, like a decade plus now? I've ran swiftjectivec.com on it, and it's always been the perfect middle ground of taking care of the cruft I don't want to deal with, while allowing me to get my hands dirty and code when I want. Some of my favorite software ever.
I have some old jekyll websites that I only very infrequently need to update. Each time something in the ruby / gem / bundler / jekyll chain setup is broken, and with some weird errors it is stackoverflow search time. Very time consuming, highly annoying. I postponed my last typo correction, to first make up my mind on whether to port to astro that I use currently.
Just sucks that eventually, that will happen with whatever you use after migrating too, the only difference is how long it takes.
I'm hoping NixOS or even just Nix for dev envs (or something similar) will help against this, so you end up with environments that just keep working.