Nope, you don't add /s because you think the sarcasm is generally not recognizable otherwise, you add it because of accessability and to avoid spawning useless debates.
Not all people in all situations will read a thing as sarcastic — e.g. your response to a post might be sarcastic, but the three comments next to it which were not there when you wrote it, might produce a context in which it would be read as serious by most people without neither you or your readers being at fault. But you have the power to clarify and at least on this platform a unneeded /s has more benefits than disadvantages IMO.
Explicit sarcasm markers are an important accessibility tool for neurodivergent people that might have otherwise a hard time figuring out if something is meant to be sarcastic.
Who said I didn't need them? The problem is people in the real world don't have /s markers and often aren't actually your friends and can listen actually mean you harm. Part of my neurodivergence leads to me being trusting of people when I really should not, (aka I'm gullible) and this sends me down the wrong path sometimes. Since I'm neurodivergent and have trouble with this, the way for me to get better at it, is to practice harder at things that others find easy, not for me to demand and expect the whole world change to suit my needs.
And other people don't like them aesthetically or conceptually.
It's great how we can all make our own decisions when communicating, and can ignore judgement from people who say that they are "necessary". You're treating fragmede like they brought up "/s" as some sort of virtue signaling, when they were pushing back on porcoda for attempting to impose controversial new-age grammar.
Not all people in all situations will read a thing as sarcastic — e.g. your response to a post might be sarcastic, but the three comments next to it which were not there when you wrote it, might produce a context in which it would be read as serious by most people without neither you or your readers being at fault. But you have the power to clarify and at least on this platform a unneeded /s has more benefits than disadvantages IMO.