Are fake reviews even a problem worth bothering with?

For me, the answer is mostly "no" because I just assume everything (except certain name-brand items that I did my homework on elsewhere) on Amazon/Ebay/Aliexpress/etc. is marginally-functional crap and adjust my expectations accordingly.

If anything, the only signals I go by on those sites are the number of ratings and reviews (not their content) as indications of popularity, following the "wisdom of crowds."