The problem as I see it is that the mainstream websites are not good. Search results that gave a broader range of hits than just that sort of thing would be much, much more useful.
If I want, for example, to find what laptops people consider the best, none of those sites help me.
There are sites that do some good gear reviews for relatively specialized equipment--especially not gadget/electronics. But this isn't the 1990s when PC Magazine would have a 600-page issue with a big chunk devoted to the best printers as evaluated by their on-payroll staff.
I'll occasionally put a review of something up on my site but I have neither the money or interest in doing multi-product comparisons. That's pretty much impractical outside of something like Wirecutter (which I generally think does a pretty good job).