First of all, you don't need to be likeable by dozens of people in order to be a founder. In fact most founders are not likeable.

Second, even if you are generally likeable, you cannot engage everyone in the audience from a stage.

Third, if you want to find be a co-founder, identify specific people with missions you care about and spend a lot of time brainstorming the problem and potential solutions and get a sense for their intelligence, energy, and integrity before you sign up for building a company with them which can take years and has a very low probability of success.