It depends how obvious, but honestly I don't think it's that bad. Some non-native English speakers might not get sarcasm, and it also depends a bit on culture. British people are a fair bit more sarcastic than Americans and it's not always obvious in text.

Poe's Law does run a bit rampant on Reddit

That cropped up about the same time people started calling anything and everything “trolling”.

You could make the most hyperbolically obvious joke that was designed to be picked up on, and somebody would accuse you of “trolling”.

Enjoy people who can't read tone through text (most people) getting angry at the sentiment expressed in your 'obviously' sarcastic comments.

I used to be a big proponent of “/s”. My rationale was that reddit was a worldwide site, and it wasn’t fair to exclude people who weren’t fluent in English. Plus, I didn’t want to live up to the stereotype of the selfish, arrogant American.

Now, I just don’t worry about it. Over time, I realized I could say something obvious and seemingly non-controversial, like “the sky is blue”, and people will disagree anyway. If somebody a thousand miles away takes a sarcastic statement literally, and decides that I’m an asshole, then so be it.

To be fair, that stemmed from an inability to sense tone through text. It doesn't matter if something seems obviously sarcastic to you, other people don't know you, or your sense of humor, and are more likely just to think you're an asshole or blatantly wrong

Even worse is when someone doesn't add it and someone else complains about it.

Seriously? /s /s