That is a fair point. But wouldn't an intrinsic motivation for group conformity be a competitive advantage here, instead of being coerced or convinced for it? For example ants must have high intrinsic motivation for following the group, they don't need to be motivated or convinced. Likewise, humans come with factory settings for many prosocial behaviors somewhat instinctively (e.g. mother-infant behavior), therefore the group benefit and intrinsic motivations being in alignment can be a selective advantage.

Can be certainly, but I'm not convinced it would be a selective advantage in all situations - when being coerced by a more powerful human or group of humans for example, it may be most adaptive to be pliant to the extrinsic motivation for co-operation but maintain an intrinsic motivation to act against the coercer's interest.