Apples to oranges. Those polymer filled grooves dont make it easier to make a proper stroke. Next!
I will give you that an anchored stroke is not anywhere close to a standard putter's stroke. No argument.
But what does it hurt for the 99.99% of golfers in this country to anchor their putter?
Likewise, I used an anchored putter for a few months last year. I hated it. It did nothing for me but ruin my putting stats. I switch putters to Seemore offerings and have putted better. I am not saying that the strokes are the same, I am saying that an anchored putter is not an unfair advantage.