You never needed to Force Touch an icon to delete. It has been long press since the first iPhone.
But your confusion is an example of the main problem. It’s hard to discover and easily confused with long press (if you try to Force Touch and don’t apply enough pressure eventually you’re going to leave your finger there long enough to activate long press)
I had the very first iphone and several after that before the touch thing... Long press was always the way to do that, and I never had a problem deleting hundreds of apps - I'd even released a few of my own iphone apps at that point.
Then I couldn't delete apps at all, but turning off 3d touch fixed it. Perhaps a coincidence, or some other bug. Terrible UX though.
But your confusion is an example of the main problem. It’s hard to discover and easily confused with long press (if you try to Force Touch and don’t apply enough pressure eventually you’re going to leave your finger there long enough to activate long press)