Like how FB and Google just update willy nilly and you're stuck with whatever you get no matter the workflow issues. Should be able to pick a version, even if it's a sliding window.
MS Edge uses Blink under the hood, which is a Chrome fork. The monoculture is all but here, save for dwindling Firefox and Webkit. Everything else that's popular is effectively a Chrome skin, or if you like, Linux distributions packaging up stuff around the kernel (the rendering engine).
FaaS, function as a service. Depending on how software is packaged and the expectations the richness a VM, like Firecraker, provides may be useful. Many of these tradeoffs are for velocity, I can run X easily on Y.
Do you want to learn a framework or just new JS stuff?
https://eloquentjavascript.net/ is a great way to get familiar with JS. React has the most traction behind it, although I found Vue easier to pick up. I suggest trying your hand at things and seeing what sticks with you. I've been having a blast with Vercel.