The previous 3 WS were the lowest rated in history. This is just following the recent trend. People just don't care about MLB that much anymore. They like going to games here and there. Population has increased so there are more fans to buy more tickets so it looks like there is more fan interest, but it's just not really there except for casual fandom. Also, MLB has done such a s*** job of marketing players that people in other markets have no real clue who plays on other teams. Corbin Carroll, Zac Gallen, Corey Seager and Marcus Semien should be household names.