I played WoW when it came out but I thought even then it was clear that their adverts and cutscenes weren't trying to fool us into believing that was the gameplay. I can't speak for StarCraft, but in WoW they were labeled as Cinematic Cutscenes. Most mobile games ads i see are made to look like gameplay, even the picture OP posted.

The Starcraft cutscenes are awesome, both SC1 and SC2 as well as both games being awesome. Obviously you're not gonna get movie level graphics in game. RTS games aren't about graphics but about how the game plays and both Starcraft games are still the best RTS out there.

Fuck modern blizzard but they used to make some awesome games. There's a reason Starcraft is still the premier RTS to this day despite both games ages. They both play extremely well (SC1 less so but its aged impressively well) and I still play both casually.