The follow-through is so important. Take this thump hoop, put it in the ground, set the ball under the hoop, and make a stroke. My putter head went maybe 1/4 of an inch past impact and the ball rolled 15 feet. The idea that you’re supposed to accelerate through the putt, to me, is illogical. Acceleration happens at the start of the downswing, not at the bottom of the downswing.
You can also do this drill with two tees by putting them in the ground. Make the same stroke and the tees will stop the putter head.