Depending on what you want to build and how many people will contribute, the answer might vary. HTML/CSS/JS can be enough, but mostly you will need to handle st

Depending on what you want to build and how many people will contribute, the answer might vary. HTML/CSS/JS can be enough, but mostly you will need to handle streamlining browser differences etc. explicitly. Frameworks are popular because they can help to streamline these issues. Also there is mostly an eco-system built around these frameworks, so you don't have to build every component from scratch for example. From a business perspective it's easier to say we're hiring for this specific framework (React, Vue etc). vs. we have our own rules and styles. Finally these frameworks also have a social function. It's like a style or taste preference, where a group shares the same preferences.