I think it's amazing that Blizzard of all companies, made 0 effort into making the game more accessible to their general audience like they have for every other IP they own/operate. Like I know nobody here probably plays WoW, but WoW used to be a much much harder game to play, classes were harder to master, things were harder to get done in general, but nowadays a great deal of it is automated in terms of getting people together to do things, and the classes are 10x easier to play then ever. Overwatch is probably the easiest FPS on the market to get into, even if you're awful you can have a great deal of fun playing this, and you can Q(Ultimate) for the win without regard to your skill level, eventually even the worst player can get play of the game because of this. HOTS goes without saying, it's the easiest MOBA on the market to play/get into vs DOTA2 & LOL which pretty much requires you understand that 1 map people have been playing on for 15 years and item loadouts for characters. Hearthstone is Card Games made easy. Diablo kinda screwed up initially with 3, but corrected the ship into faceroll adventure/loot game with Reaper of Souls which was for the better.
There is so much wrong in there...
WoW being "harder" is a difficult comparison. I think most people would tell you a lot of the Mythic+ content now is substantially harder than anything that used to exist in the game. Things like LFG and LFR certainly are easier, but it's a false comparison since there is still Normal, Heroic, and Mythic to account for, and most of the complaints I hear are from people who think all that story content and gear should be completely gated behind overtuned (a lot of raids in Vanilla and TBC were overtuned if not completely unbeatable--C'thun) raid instances that take weeks or months to clear for even the best guilds.
On top of that, the classes are not substantially easier to play, they just removed a lot of the clutter and janky mechanics of certain specs. I played Enhancement through MH/BT/SWP, and had to deal with Totem Twisting (Drop Windfury Totem for 0.5 seconds to apply WF buff to group members, then switch to Grace of Air Totem to give them a different buff for 5.5 seconds until WF wore off, rinse and repeat the entire fight), which was manageable, but certainly not fun. A lot of the difficulty in classes now boils down to maintaining a very tight skill rotation and player awareness and positioning--fights are quite a bit more complicated than "Stay away from the Tail and Head". Yes, you can clear LFR content with ease, but it's not an accurate representation of the difficult part of the game.
As for Diablo, while the story sucks, the game has near infinite progression, and while it's not all convoluted skill trees, there is a ton of nuance to building characters--2 people could have equally geared characters and one could struggle with GR50 where as the other could push GR60+. I think you're also downplaying how different the game is from when it initially launched, and how high quality Reaper of Souls was. The story was substantially better in RoS, and it changed a majority of the complaints that people had about the original game. The pacing was much better, the stories more interesting, and the locations a lot more menacing.
Heroes of the Storm is definitely a MOBA/ARTS with training wheels, but that's by design. Blizzard designed the game from the ground up to get rid of the 30+ minute matches their competitors were offering, and instead focus on team-oriented objective-based maps, that are easily done in ~20 minutes. You're also grossly oversimplifying the complexity of DotA 2. It's a lot more than understanding a handful of heroes and item builds. There's probably thousands of item/skill interactions, different map interactions, character movement, pathing, pull times, animation cancelling, and dozens of other aspects of the game that take years to fully understand--I know this since I occasionally see things pop up on Reddit I didn't know about and have been playing DotA since around 2005.
As for Starcraft II, the campaigns are probably the best part of the games in my experience. Online play is really frustrating and I think mechanics heavy RTS's are going the way of the dinosaur. They are solid games if only to play through the interesting and varied single player campaigns, but Blizzard kinda dropped the ball on SC2--SC:BW was hugely popular not only for its finely tuned multiplayer, but also UMS Maps, and the Arcade in SC2 never panned out as well as it could have.
Starcraft 2 seems to be designed to preprare you for multiplayer by pressuring you. But i dislike multiplayer in RTS and this will not change. I have not bought LOTV yet.
