I notice that the distribution is heavily skewed where the HTML/CSS/JS camp is using it for their blog or 1-person project and has been doing it like this for a

I notice that the distribution is heavily skewed where the HTML/CSS/JS camp is using it for their blog or 1-person project and has been doing it like this for a decade, where the React/framework camp are the people who have done both and are working on large projects. The basics of React are learned by 1-month novice programmers in 2022. You don't even need a build system (which is even setup for you with Next or create-react-app). At it's core, it's just a file which contains "super"-html that you can update state more easily.