I don't really care if I get spoiled lol, in fact, I actively look for spoilers.
Usually, before jumping into any game, I'll go hunt for spoilers to judge whether it's actually worth my time.
When it comes to CGs, even if I stumble upon a massive spoiler CG, like the ending or a character dying and stuff, it just lets me know what I'm getting into, whether it'll annoy me or make me more hyped. Plus, just seeing a CG doesn't immediately give away the context or how the story builds up to that point, so yeah lol.
As for accidentally playing a route that spoils all the other routes? Just like YummyYum said, I find it absolutely hilarious playing through those lol. Watching the characters lose their minds or suffer while I already know exactly what's going down is just too much fun xDddd