At least for me Windows Phone apps are much better or the same.
Facebook? For my usage is the same.
Instagram? 6tag is much better than Insta Beta for WP or even any Instagram for any device. I can even download pictures on 6tag. It's much more fast than original too.
Waze? There's a lack of minimum functionality, but works fine AND don't have AD. Nothing better than drive without a lot of ad trying to make you hit or just pick the wrong street.
Email client? There's no comparison at all. Outlook is the best for W10M and the best email client ever.
Calendar? Same than email client.
9gag client? No comparison too.
Browser? Safari is better, but Edge is almost there. No comparison to Chrome, the worst mobile browser. Edge is more reliable, fail proof and faster.
If you aren't a appholic that want every useless app instaled on the phone, Windows Phone is the best choice possible.
I like how you broke down the apps that you use, and your response shows that it is truly a case by case basis. For you, it works well enough.
For me, apps I use on a daily basis are always crashing or are just inferior. Some apps are okay. For your breakdown, I'll do a brief one myself.
Hoopla? A non-starter, doesn't even exist on Windows Phone. Strike one.
OverDrive? Hasn't been updated in 3 years and crashes all the time. Also hitting back button takes you back in the book. Since I can use the browser for it, I'll give it half of a strike.
Kindle? Also hasn't been updated in years, and it also has the same deal as OverDrive with the back button sometimes. However, it does sync its place so I'll also give this half of a strike as well.
MLB At Bat? It has been pulled from the store, and that app is more than just the scores to me. I need updates, and team news, after all isn't that why I have an app? The other baseball apps are nice, but they don't push the news as much as I'll like for just my team. Strike three - I'm out.
I use these apps too often to settle for not having them not exist or not work as they should.
Otherwise, Outlook is nice, so is GroupMe, and Skype is just okay. The third party apps for Twitter, YouTube, and Feedly are great though. For your situation, it works. For me, it doesn't. And yes, the Android apps are better for my listed apps.