Sometimes they do. I started using Pages on my iPads several years ago. At first, it was a bit wonky. One annoying bug was that the automatic spell check underline was offset in some Microsoft Word documents created in Word and then imported into Pages.

So, I wrote a review of Pages, mentioning that bug. An Apple engineer sent me an email asking if I could send screen shots and the document file. I did, and by the next update, the bug was gone.