What's the issue with web components that they have never took off?
(1) Poor native browser support until recently, Firefox originally refused to support Web Components v0 at all (now called Custom Elements in v1, they are supported in all evergreen browsers mostly).
(1a) Available polyfills were initially buggy and had severe performance issues on older browsers.
(2) Lack of proper templating, though I personally quite adore template literals and approaches like e.g. `lit-html`.
(3) Lack of robust styling API - custom styles felt coarse and tacked on in v0 especially, and were poorly supported by pre-processors like LESS/SASS.
(4) Lots of impedance mismatch issues connecting standard JS/HTML/CSS libraries with the Shadow DOM.
The main use right now is as target for framework independent design systems / component libraries.
Looks pretty straightforward, and there isn't much of an API to begin with. It's just plain HTML, CSS, JavaScript and DOM APIs.
Exactly. The entire history of web development has been about finding good abstractions around the horrendous DOM APIs.
And that's before you start talking about the need to roll out your own solutions like state management for WebComponents.