I was surprised to find that Stereophile gives a three-year lifetime to these products. If there is truly a reference product with a great design that does not need revision every three years, you lose. You won't see it on this list. The other choice is the manufacturer has to re-submit the product for a new review which is not too interesting. These reviews are specifically looking for what is new and interesting.
Stereophile's 2021 products of the year
And wow! Schiit Audio 20w Class-A Aegir stereo poweramp made it into the A rating.
https://forum.audiogon.com/discussions/stereophile-s-2012-products-of-the-year
Cheers George