> There are already many steps taken to improve DOM performance over these years. However, DOM is designed for documents. The performance can never be good enough when it is abused for non-document usage.
JavaScript was originally designed for simple tweaks, but we've significantly expanded and improved the language over the years to adjust it for what it's used for *today*. I don't see why DOM is special. Sure it was designed to handle small, unchanging documents, but it's used for much more now, just the same as JavaScript. Also it's worth noting we're talking about Google Docs here, so it looks like DOM fails even at its intended use-case (I'm saying this *mostly* jokingly).
> Because other browser engines are unlikely to adopt these APIs just so that Google Docs can have better performance. Not to mention that these new APIs will take years to be present in every user's devices.
We wouldn't have fetch, canvas, async/await, PWAs, websockets, etc. if those things had to be available immediately and/or be guaranteed to be adopted. I'd rather it take years to get improvements, but eventually have them, than not doing anything and still be talking about how bad X, Y, or Z is 10 more years from now.
I'll take FLIP animations as a specific example. If I want to have a box animate from one part of the page to another (where it's position in the DOM hierarchy changes), we're having to do all kinds of crazy gymnastics around when you read the DOM, when you write to it, how do you update it, etc. And even still, you're unable to do this without using JavaScript animations (if your box contains content and it happens to change size, we'd have to do a reverse scale animation on the content).
This is stuff that's trivial in iOS and Android, and commonly used. In the web land, we're stuck doing this poorly both from a development point of view, and with bad performance, resulting in poor end user experience.
The FLIP hack has been talked about for 6+ years [1], and yet here we still are, unable to simply move and animate a box from one place in the tree to another. Want nice drag and drop interactions? Good luck. Limited animations, or slow, and often both.
Why are we getting articles from Google about how it's bad to change the size of something on the screen [2], instead of seeing improvements to the underlying APIs that cause it to be slow in the first place? If a hacky JavaScript based solution is able to make this performant, surely a native API would do better.
The DOM has to evolve to support interactive apps in a performant way, or risk being replaced by custom things like the canvas or WASM, that are not easy for machines to parse, that won't have nearly as much consideration for accessibility and extensibility. That aren't as easy to enforce good usage of, or share knowledge about. It should not be "DOM is slow, oh well", or "DOM is slow, lets drop it", or "DOM is slow, so lets build a JS scaffolding around it (VDOM)." It should be "DOM is slow. What are the contexts in which it matters most, and how can we improve the APIs such that it can natively do those things performantly and easier?" Be that better selection APIs, animation APIs, better ways to read/write to styles, the list is endless. The DOM is slow, but it does not have to be slow. We *choose* not to make significant improvements to it, and one can come up with plenty of reasons why or excuses for it.
My point is that we should choose to improve it, because the alternative will lead us down a worse path. Years of neglect has led us here, where Google, a browser vendor themselves, has to give up on DOM because it's bad. This is fundamentally messed up.
[1]: https://aerotwist.com/blog/flip-your-animations/
[2]: https://developers.google.com/web/updates/2017/03/performant...