I am not big on the built-in apps. I use Fantastical, Shoot, Castro, Soulver, Spark, and Drafts as alternatives to Calendar/Reminders, Camera, Podcasts, Calculator, Mail, and Notes.
I write to the Health app with third-party apps too, but you know, I've been using the iPhone as a way to track health stuff since the App Store opened. For me, the APIs make it manual and more accurate, but I don't necessarily need them.
I don't do iCloud backups either, prefer to keep those on my Mac.
I mostly just type on my phone, lots and lots of typing. And take pictures. And answer the phone when people call me.![]()
As you don't do iCloud backups, I hope you use encrypted backups on your Mac because otherwise all that health data isn't getting backed up...