I edited this into my original post just in case but I was too slow.
This is kind of a launching pad to all kinds of shaky arguments that ignore how long certain games have been on the market, how many platforms these games are available on, etc. There are many windows for bias, but the fastest-selling games in the series are RE2, which sells faster than RE7, which sells faster than RE6; and, the only common denominators are an increased focus on horror (w/ stalker enemies), titled as mainline entries, and third-person perspective. You could include RE5 if you wanted, but it came out in 2009 - so, it's sold much slower than RE6, much less RE7 and RE2. If you want my opinion, I think perspective is secondary to subject matter, visuals, and more/other substantive gameplay styles (multiplayer shooting, survival horror, etc.).