If you choose a product with a rating of more than 4 stars averaged over a lot of customer reviews, it's pretty decent data to go by. For routers, there are a handful of good brand names you can safely pick from. Even so, you admit you don't actually read the reviews, just go by the total number.

It's harder when choosing a product like a washing machine which has a lot of options between 3-4 stars in any given price range and no clear winner.