ELI5 What are Web Components

Making your Own Lego

So if you want to see a website you need a tool called a browser. The browser is basically a box of lego pieces (HTML elements). Everyone agrees on what goes into the box, such that people who built websites can reliably choose which bricks to use to build them.

About 10 years ago, some of the people who make and fill up the boxes of lego (browser developers) thought it would be a good idea to include a 3D printer in the kit, so that website builders could invent their own kinds of bricks. The kit-makers started writing into the kit-making recipe (the HTML specification) about how the printer should work and what it should be able to do (custom elements, Shadow DOM, <template> elements, etc).

Doing it the Hard Way

Now, before this, the lego box already came standard with some Technic pieces like motors, gears and pulleys. This let website builders do things like add animations or cute little interactions to their pages. At the same time that browser makers were starting to write the first draft of the 3D printer part of the lego-box instructions, a small but very loud group of website builders started convincing other website builders that the best way to build lego was to put the technic blocks together to build a complicated machine that would stack and unstack the blocks for them (javascript frameworks). In other words they thought that instead of people getting a completed lego work (website), it was better to send a lego technic schematic for machines which would then put the intended lego work together for you.

Technic is pretty cool and you can make really neat stuff with it, but most kids just wanted to play with the lego work (HTML), instead of with a technic machine which builds lego works (framework SPAs). It's kinda weird because Technics is supposed to be for adding cool mechanical stuff on top of the lego work (progressive enhancement), not for making lego-building machines. The kit-makers are supposed to be in charge of that kind of thing, instead.

What Web Standards have to do with Global Inequality

Anyways, the rich kids that had lots of lego and only the fanciest and most powerful technic blocks in their boxes (expensive iPhones), wouldn't really notice the difference because their fancy technics blocks would build the lego work (client side rendering) really fast, but most people in the world didn't have the fanciest legos, they only had the plain pieces (low powered Android), so having to play lego this way was slow and boring, and some couldn't play at all (poor accessibility practices).

Now you'd think that each standard lego box coming with it's own 3D printer would improve things because then everyone could get nicer pieces faster and website makers could concentrate more on the final work than on the inner workings of the technic machines, and actually in a lot of the houses in the neighbourhood that's what happened. But at recess time on the school yard the cool technic kids (framework authors) just yelled louder than anyone else, and a lot of the younger kids ended up thinking that the only way to build legos was by spending most of their time tweaking complicated technic machines, instead of snapping bricks together.

Framework Hype

Most of the older kids and some of the younger ones went to play a different, less educational game (native apps) and the kids left behind didn't have such a fun time playing lego anyways (framework churn) - actually most of them just had to sit and watch (high barrier to entry) while the cool kids argued about the best way to connect a rubber belt from one piece to the other. What's worse, is that even on the cool kids side of the yard, where you had to start building your technic machine early in the morning if you wanted to see your lego work built by recess, the younger kids have to choose which bully to hang out with, because they each have their turf and like to punish kids for hanging with anyone else (lack of interop between frameworks).

So now the schoolyard sounds like it's full of happy kids, but it's mostly just a handful of bullies loudly talking themselves up and their peers down while the rest of the school either builds legos in the lunch room with cool 3D printed custom pieces, or gives up on lego altogether and spends recess sitting silently in the library scrolling tiktok.