the only device you'll ever need provided you could only have one device.
Disclaimer - I have all of these devices. SmartPhone - Tablet - Desktop - Streaming Box(es) - Smart Speakers - Smart Watch - smart MR glasses ...
What I use most in my job and privately is my iPP - the iPhone is a niche filler when it needs to be more portable but the current iPhones are already far to big for my taste - an AW plus a iPad mini is the prefect setup IMHO
Nevertheless the iPhone is always with me - mostly as a radar warner in the car