RT is certainly losing my favor, it's Disney garbage everywhere, the top movies consist of whatever came out in the last 2 years, the algorithm just isn't good.
Their algorithm is mostly unchanged as far as I can tell. They take a bunch of critics and aggregate their reviews as positive or negative. Therefore most of their highly recommended movies are, and always have been, predominantly broad-appeal films that are mostly inoffensive.
RT's increasing popularity has created pressure to make more mass-appeal mediocre movies, as movies are rewarded for being "watchable" and get no bonus points for being "excellent" (and excellence which might turn off segments of the audience if any controversial choices are made en route).