Hit 5 x 27-metre pitch shots from the same spot with a 2-piece golf ball.
No cheating and retaking of chunked, or thinned shots.

Measure the distance of each from the target and calculate an average distance.
If your handicap is > 12 and your average is under 15’, you’re doing well.  

Now repeat the test from exactly the same spot using a premium golf ball of your choice.
Has your average distance materially improved?

If it has, was that because you didn’t miss-hit any?  

Of course a premium ball helps. Of course a new wedge with clean grooves and the latest technology helps.
But you know what would make a material impact to your ability, to lower your average distance from the flag?
How much of an improvement would you get from one lesson?