2
Kitchen shears
Didn't stick
Shears were a genuine improvement and I used them for months. They are great on pizza, quesadillas, anything flat.
Two problems. They need both hands, which is the same problem as the knife. And they are hard to size consistently, so you end up with one piece that is fine and one that is too big, mid-air, over a bowl.
3
The pizza cutter
Didn't stick
This one gets recommended constantly and I understand why. One hand, rolls fast, no sawing.
But a wheel scatters. Pieces shoot off the board, sizes come out wildly inconsistent depending on how hard you press, and it does nothing useful on anything with any thickness. Great on toast. Useless on chicken.
4
Cutting at the table, with whatever is there
Didn't stick
Restaurants, grandparents' houses, the park. A butter knife and a paper plate.
Every meal out turned into a negotiation with a server for something sharper, then a small apology for hacking away at a plate in public. This is not a tool problem so much as a fact of leaving the house, but it is the thing I most wanted a fix for.
5
Buying it pre-cut
Didn't stick
Pre-cut fruit, pre-portioned pouches, the little trays. It does remove the task.
It also costs several times more per pound, the selection is narrow, and none of it helps at dinner when you are serving what everyone else is eating. The task came back within a week.