JSX is not a "component ecosystem". JSX is a way to embed HTML-like syntax in JS and convert that to function calls. It does not grant any additional capabilities besides letting you write `<div>` instead of `react.createElement('div')` or `div()` or `h('div')`. Are you actually meaning react when you say JSX?
Builders, polyfills, linters, components, frameworks, etc. existed before and exists independently of JSX and react.
> The underlying HTML no longer matters except to the lib maintainers.
Would you hire a frontend dev that didn't know the difference between a <head> and a <body>? A <input> and a <select>?
Even if you would (which IMO is a very bad idea), the only reason you can build anything is that there is a well standardized base, which consists of HTML, JS and CSS. If those where not as stable, standardized and consistent as they are you would not be able to build rich web apps on top.
Builders, polyfills, linters, components, frameworks, etc. existed before and exists independently of JSX and react.
> The underlying HTML no longer matters except to the lib maintainers.
Would you hire a frontend dev that didn't know the difference between a <head> and a <body>? A <input> and a <select>?
Even if you would (which IMO is a very bad idea), the only reason you can build anything is that there is a well standardized base, which consists of HTML, JS and CSS. If those where not as stable, standardized and consistent as they are you would not be able to build rich web apps on top.