[kllrnohj]

> HTML is great for plain forms

I'm not sure I'd call that an "interactive UI" though as that's pretty much a static layout. Which yes HTML is fine at handling.

> Browsers are also good at graphical outputs.

They're okay graphical outputs, not good ones. The feature sets are good, but the performance is all over the place and pretty much always sub-par as they are very defensive against content. Meaning the difference between the fast path (so plain scrolling) and the "slow" path (nearly anything else) is absolutely massive. Even things that are all but free on native toolkits, like just animating a color, can tank browser performance.

> But we go where the users are

Of course, which is mobile apps ;)

No but the point is just browsers aren't slow because they are an OS inside an OS. The layering isn't the cause of really any problems other than the binary size of the browser itself.