Figma is the gold standard when it comes to performance and optimization, and is basically a native app that happens to be inside your browser. The co-founder and previous CTO Evan Wallace also created esbuild which powers most of the modern bundling tools.

The only other web app I can think of doing the same thing is Google Docs, which uses it's own canvas based renderer with an svg overlay for accessibility. I feel it's telling that Google thought leaning on their own browser (through HTML/CSS) wasn't even good enough for typesetting.