I think most people who use it are just scared from the uneducated downvotes/ backlash and I think it just ruins the sarcasm.
I started to avoid using it on other social media as it seems kind of dumb.
My opinion for it on Lemmy is mostly the same but it might work better here if Lemmy had a sarcasm tag instead(the same way NSFW tag work)of /s to signal the sarcasm instead.
No, there isn’t. Tone is inflection in speech and body-language. In text, you might reasonably think it could be inferred, but that doesn’t mean it can’t be conveyed. And if someone is missing the inference, piling on “evidence of tone” phrases could be misinterpreted as “more proof of conviction”.
Use /s. If you get downvoted because you didn’t, that’s on you.