I finished a side project web app recently and am about to come upon a chunk of free time before uni starts again. It struck me how difficult it was to do things like:

• Make an animation performant (lots of CSS properties trigger paint or layout unexpectedly)

• Make components with good keyboard accessibility (not just tabbing), common mobile gesture support, etc.

• Do styling properly (CSS modules aren't quite cutting it, and on the perf side sometimes recalculating styles takes up to 50ms!)

I'd particularly like to improve the performance story in the frontend world but I'd be interested in creating or contributing to anything (build tools, libraries, linters, etc.) that makes it easier for devs to make a nice user experience. I was going to experiment a bit myself with things like shadow DOM, wasm, and web workers to see if those things might be suitable for the mainstream web (for wasm we have yew, for example, but it's niche). I thought that first, I should get the opinion of web devs more experienced than myself.

To repeat the title question: What does the frontend dev world need to make better applications?