Part of the issue here is that marketing doesn't care about reliability. Look at Office 365 for example. Can I think of many useful features to add? Not really. Can I think of any bugs, flaws and irritations to fix? Hell yes!
If MS were to say "We're not implementing any new features in 2019, instead we're focussing on fixing bugs, crashes and general irritations" I'd be delighted! Instead, MS (like everyone) decides to focus on questionable gimmicks when quality improvements would have a much bigger impact on user satisfaction.