I totally agree, simpler is better. Except for extenuating circumstances, teams working anywhere remotely close to each other should aim to stick to the same technologies and practices. If that's vanilla js, sure, go for it.

I'm not arguing everyone needs to move to react. I'm saying the opposite. Stick to the tools you know. I once worked in a strict java-angular.js shop, and it was awesome. Everyone was familiar with the tech and the company saved energy otherwise wasted on tool-related decisions.

My point is this

> it is more of a flex in this SPA era to show you know how to make a website the old-fashioned way.

is not valuable to me at all. If I were giving advice to a new programmer, I'd tell them learn the basics first, like your html, js, css, and then familiarise yourself with one of the frameworks. Then if you want to build your portfolio, build it in whatever you like, but for people at that level, it can be a great chance to practice and show off their skills to employers. If you're shipping 2MB, who cares.