You're not the only one. At least some of the them have spoilers that can only be recognized as spoilers once you get far enough into the story. Like you'll only understand that it's depicting a certain battle at a certain location once you know of that location.
Video games are REALLY bad at this, too. They basically show you every playable character in advance, or who your enemy will be, and so on. I just don't understand why they do this. I skip every RPG intro for this reason and I've never regretted it.

I don't think I've seen a single one of these that actually spoils the show in an obvious manner. Most of the time it's foresight from being familiar with the story and being able to understand the foreshadowing in the OP. Even with stuff like Gungrave which is infamous for spoiling itself, I don't think the average viewer would get spoiled badly by the OP unless they think too hard about it, at which point it's also their own fault.

Having said that, usually I watch the OP the first 2 or 3 times, then for subsequent episodes I leave it playing while I get up to get a drink or something, and for the last couple of episodes I watch it again.

Video games and VNs are definitely much worse about this. Especially VNs, so many of them include CGs from climactic scenes in the OP.

I either overthink things or don't think at all when I see something that hints or semi-spoils something. I think it's an occupational disease of sorts from watching romcoms back in the day where misunderstandings reset things to how they once were.
It's actually so bad that there have been a couple occasions where a character could straight up say "I like you", and I'd still be confused on whether that was a confession or not.

what kind of a file format is jfif i never saw that before

maybe im just being a baby but when I see a charachter in the OP that hasnt been introduced yet i think its a spoiler. and if I see that they are a good guy or bad guy or their role in the team its a spoiler.
like for example the other servant introduced in the opening of Mobkara, or Robin joining the team in One Piece 15 episodes before she does

It's one thing if it's for an adaptation. I do think that they should probably not do it as much for adaptations, though if I'm watching an adaptation there's a 90% chance I'd already read the source material (at least up to where the anime covers) so it's rarely an issue for me.

For originals, the information being in the opening is intentional and can't really be called a spoiler. I haven't really seen very often anything important spoiled in anime original openings anyway though.

The only thing that bothers me is when a cute girl shows up during an episode but they aren't in the OP so I know they won't feature much.

it's called foreshadowing

>>91932
In terms of adaptations, if the opening is showing something before you're supposed to know it in the source it isn't foreshadowing. Like someone above mentioned showing Robin as part of the crew while she was still a villain in the series itself. And adaptations tend to be the worst at having spoilers in their OPs.