World of Warcraft is a subscription game that is developed by Blizzard. Following the allegations of sexual harassment in the media at Activision-Blizzard has hurt the goodwill of the company. Players are also grumbling over the lack of new content for the game. Some told me that it has been a few years since any new content has been seen.
Many have abandoned World of Warcraft for other MMO games. Elder Scrolls Online is a popular game that does not have a subscription attached. League of Legends is a competitive subscription game. ESO has some DLC which expands the game world substantially.
Destiny 2 is free to play and it has an extensive game world. Bungie has done much to expand the game which is now one of the largest games in Steam. Destiny 2 is also one of the most popular games on Steam.