I'm not suggesting that your ability has changed, rather the game has changed and your previous ability might not be as applicable. If a shorter golf ball posed a noticeable negative impact to your handicap under your current playing conditions, it would seem logical that one who wants to play at the same level as before would need to make adjustments, but that would not entirely mean just "playing better".
The "change" they could make would be new ratings for the course. That way your skill level (which hasn't changed) would be reflected by your handicap index not changing.
I'm not convinced that a change in the ball will have a wide spectrum impact on players handicaps as some have suggested.
Thing is, we can quantify how many strokes gaining (or losing) 25 yards off the tee will affect scoring averages, handicaps, etc. Broadie did it. Lou's done it. I've done a little bit of it. You can believe in the tooth fairy all you want, Ben. Doesn't make it real.
Edit: Let's say a player loses 25 yards on 14 tee shots a round. My home course has tees that are 6500 yards and rated 72.2/141. Add 350 yards and that's almost 50 yards longer than the next farther back tees, which are rated… 74.0/145.
And that's to say nothing of the second (or third) shots. A 6500 yard course that plays even 5% longer becomes that same 74.0/145 roughly (6825), and at 10% longer becomes 7100.
If we were to go back 15 years, it would not be surprising to find similar comments spoken about the grove rule change impacting players performance.
I lived through it, and it would surprise me. The groove rule was mostly for PGA Tour players… and it wasn't even set to take effect until next year for regular golfers. Bad example.