Caution: this seems to be an ad for "quadratic", which promises "The spreadsheet with AI". I'm sure it will turn out much better than Excel, a spreadsheet without "AI".
“Nice” doesn’t mean “well suitable for writing a compiler in”. It’s strange to think that all languages should be equally good for writing all kinds of things, and choosing a web language for a non-web task is doubly strange.
It’s not obvious from the text, but the compiler was previously written in TypeScript (which was kind of a strange choice for the language to write a compiler in).
I’m pretty sure they didn’t mean “exponentially more” in the asymptotic complexity sense. They could be both O(N log(N)), but with dramatically different constants.
The name “best practices” kind of implies that they actually are practiced somewhere. So it’s different from theoretical abstract ideas “how we should write software”, which maybe nobody follows.
It’s not “optimized for desktop”, it only works on desktop. I think it’s hilarious when something plainly doesn’t work and people say “oh, it’s not optimized for this case”. That’s now what “optimization” means.