Being the lead or solo performer requires good performance skills. Being a good side man (person) does not necessarily mean you have to have good performance skills but you do have to have basic stage presence. From the standpoint of personal evolution as it pertains to your music skills, any type of performance experience will develop and build growth and skills. Gaining confidence and skill on stage translates to better musical skills overall. Other than Shirley Temple and Michael Jackson, most folks need to get some experience before they can present themselves as a performer. We may progress from learning our instrument to playing music with a friend or family member, to "jamming", to the stage. Each of these steps teaches us something about ourselves, our music, and we gain skill and confidence. All of it matters. One of the inescapable realities of music is we need to be in a constant state of striving to progress. Remember how stressful it was to learn your first chord? Your first bar chord? Your first scale? Okay, it wasn't stressful, but it was strife. Keep putting yourself in a position of strife. Learn and grow. Challenge yourself to get to the next level.
The one you'll keep