The opposite of "more sidelined" could be viewed as "involved" or "active." While being sidelined often connotes being left out or excluded from something, being involved suggests a level of participation and engagement. Similarly, being active implies movement and a sense of agency. Other antonyms for "more sidelined" might include "central," "prominent," or "significant," all of which suggest a level of importance or prominence within a given context. Whether in social, professional or personal settings, being on the opposite side of sidelined can imply a sense of empowerment and involvement that can be both enriching and fulfilling.