Ignoring node.js for the moment, JavaScript is a hot language now that has stood the test of time and survived multiple ages of the web. It is a sound language and ultimately a sound platform with significant investment in its future. For a language in general, I think JavaScript is hard to pass up.
Node.js is basically just the server platform built on top of JS. It keeps abreast of current language versions, is quite powerful and flexible, and has an uncounted host of modules solving every problem imaginable available via npm (or yarn, or pick-your-module-installer-of-choice, dime a dozen these days.) Node is quite mature these days, broadly supported, can perform very well (I run some fairly large systems on node), and is a breeze to work with.
I don't know that I could quite say the same thing about Python as about JS. Python has been around a long time, but its popularity seems to come in waves. It's hot one moment, then not really thought about the next, then hot again. Interesting language, but I wouldn't consider it as the basis for a broad career myself. I have always found it more useful for niche applications and little needs here or there. I've never seen things of the same enterprise-scale built with Python (think Angular, React, and major platforms and systems such as Microsoft Office 365 (which uses ReactJS now)).