Something to consider is that Leonard Maltin, Ebert and Siskel all were getting their film-review starts in roughly the 1970s. I'm not quibbling specifics. The point is they gained an audience back when people were only just starting to be given more variety in their sit-com entertainment, the big shows being All in the Family, the Jeffersons, and MASH (things like that). Another big thing, though fading out back then, were variety shows. The popularity of variety shows was why someone tried doing that horrible Star Wars Holiday Special.
Siskel & Ebert, with their weekly half-hour film review show, Sneak Previews, was the equivalent of a sit-com episode that also provided information (i.e., entertainment news) and a bit of variety (i.e., it was hit-and-miss whether you'd care for a given review, but just wait a few minutes for them to move onto the next review). Keep in mind they interspersed their podcast-like talk-talk with video clips from the film they were reviewing, otherwise even back then it would have felt dry.
I think Maltin's film reviews on television came later in the early '80s, but I never followed that. But his main thing was the film dictionary he published back before the Internet. Just keep in mind that his dictionary was just as entertaining to look through as...a dictionary. It was a good resource if you wanted to get a quick film rating and synopsis.
So these days there are a handful of knowledgeable film reviewers, but most people are only so motivated as to type in a few keywords into a search engine field and just go with whatever comes up. I've never seen Internet film reviewers actually advertise and promote themselves, such that they might become more mainstream. Film reviewers just seem to add their link the the reviews section of IMDB and then cross their fingers.
It's the same deal with respect to game reviews. You're providing some entertainment, a bit of eye candy, and some information. But the game reviewers just go by word of mouth, so for casual gamer (i.e, the big majority) they again just type a few keywords into a search engine field instead of going to that "well regarded" game reviewer they heard about.