So I've now had the delight of upgrading to an iPhone, and am stuck with the stupid new recent apps process of side scrolling thumbnails of each app. This is a big downgrade in the basic functionality of this. You can only see the last app used, so have to scroll for everything, even split screening or pop out windows are now more laborious from here.
How do i get it back to the original or replace it with something like the original that was a fast effective method of switching between apps ?
I agree 100%. Especially with being only able to scroll through one app at a time. Good Lock and Task Changer in the Samsung App Store will let you choose other recent apps layouts.
I will add that disabling the stock home launcher through ADB will give you back the stock Oreo recent apps. If you want to know how to do that (easy and safe) you can read up here.