I would find this more compelling if we were not discussing a trillion dollar company that employs tens of thousands of programmers. The One Drive performance is so bad I cannot imagine anyone has put any effort into prioritizing efficiency. Naive, first effort attempt was packaged up and never revisited.
While that is true, its really not easy to do without re-writing from scratch and scrapping a load of features which is organisationally difficult to do.
What large piece of software with a user interface do you work with that is actually fast and stays fast? For me, its probably just Chrome / Firefox. Everything else seems to get slower over time.
