Years ago, they really drilled into the performance of the various products they compared and frequently the winner was a specialist product from a brand you had never heard of, but it really was the best on the market. Wirecutter articles did good testing with defined rationale that might not be up to laboratory standards, but it was enough to clearly identify which products were offering the best performance. When they labeled a product "The Best X", you could be fairly confident that it was going to outperform almost everything else on the market. They tested everything from the highest range products to the garbage chinesium specials and if you read the entire article, you could see where some products might outperform in certain areas, but under perform in others, letting you make an informed decision that wasn't simply picking the "Winner". Effort had clearly been put into discovering a full range of products instead of simply comparing the amazon options. Any product that was disqualified from comparison had a clear and reasonable rationale.
Starting around 2018 the quality of testing plummeted into clickbait territory. Many articles appeared to justify their choices entirely based on reading amazon reviews without actually putting hands on the product, a theory reinforced by waves of comments appearing that despite a wirecutter recommendation, the product was absolute junk. My personal "Wirecutter is a lost cause" moment was when I was looking for a new comforter and the writer had simply disqualified every single option that was polyester based because "I don't like how polyester feels." That's not good testing. That's opinion. If I wanted subjective opinions on products I wouldn't be at Wirecutter.
For an contemporary example, pull up their "The Best Drill" article. The reviews highlight things you could discover from holding the drill and looking at it. The testing is a single test performed by a single person with no edge cases or alternative uses considered. If ergonomics are such a critical consideration that it gets entries shot down, shouldn't you have multiple people testing to see how different models perform in different people's hands? Furthermore, the only products tested are mid-range household drills available from big box stores. Nothing from the professional brands like Festool or Hilti or some brand I've never heard of. No explanation why I shouldn't just buy a Harbor Freight special for half the price. No explanation why any other consumer-grade brands weren't included. The articles don't provide "The best drill", they're providing "The best consumer-grade drill for light duty work", and this attitude has spread to every corner of the site. You can't go to wirecutter and find a specialist tool that outperforms the commonly available options any more, because they're not even including it in testing.