In Excel, I can reference cells using Indirect() and spell out the cell and row number. The same can be useful in PowerApps for scalability.
Suppose you have a giant table with several columns. If you wanted to Collect, Patch, or Update, you would need to specify each column you want to modify in each instance. If you could tell those 3 functions to modify a column by indirectly looking it up in a gallery, you would have more flexibility. You would only need to edit the gallery entry if you want to change what all your other functions record with an Indirect ability.