I can't say what's driving all the playerbase losses but: They stopped development on Diablo 3 a long time ago. It doesn't have the staying power of more modern online games where new content is added continuously. They stopped development on HotS, which never achieved the same level of pull as League of Legends. Overwatch faces stiff competition from Valorant and other competitive small team FPSes, and also has over…
Blizzard kinda killed the RTS genre with Starcraft 1. It's basically the perfect RTS so everything that came after it seems inferior. Even Starcraft 2. There are still niches for specialized audiences, like historical battles with a more strategic bent, but for mass market RTS nothing has been able to beat a 23 year old game.
> It's basically the perfect RTS so everything that came after it seems inferior. Even Starcraft 2.
SC2 had a bunch of design choices that seemed to reflect a shallow understanding of what made BW actually super good. Like, how incredibly tightly units clumped together should've been picked out as an obvious flaw immediately, but instead they never fixed the underlying issue and just patched up some of the negative impacts via econ changes.