If you tell someone they are wrong and tou want them to recognize it, you need their (ideally) voluntary corperation. If you condict yourself like an asshat, most people will not do you that favour out of purse spite.
If the people know you as a tolerant person with a rational mind and a kind spirit, that is mostly driven by curiosity about the world, they will be much more likely to listen to you, because they won't assune you are just being mean. You still have the option to speak a harsh truth now and then and even this is more effective, than if you are a constant cynic that is known for this type of stuff.
If you care more about making others better you should stop caring about being right in a triumphant way. Sometimes I'd love to tell people how wrong they are, but giving them the escape hatch of feeling like they had the ideas themselves has shown to be much more effective.