I find that I can do just about anything on my phone that I might want to do on an iPad. For real efficiency I go to a laptop. For traveling about town I just take my phone. I don’t want to lug an iPad around.
Having a Desktop and a laptop and a phone AND and tablet seems way overkill. Choose your favorite 2 (or maybe 3) devices and move on. If your goal is to keep organized, it is just simpler to keep track of/update/manage 2 devices than 4.
And there is just so much overlap between a larger iPhone and an iPad anyway.
Lol, I have a desktop, a couple of laptops and 4 (actively used) iPads.
The desktop (which doubles as server) and iPads get the most use. Laptops the least but there are times when they’re necessary.
I find even the iPhone Pro Max display still too small so I gladly tote around the iPad. Both iPhone and iPad (7.9-11”) fit in my purse anyway.
If Apple gives the iPad mini full phone functionality, I’d ditch the iPhone.