Worth volunteering labs through cold-email? Other suggestions?

Hi everyone! I'm wondering if volunteer labs through cold-emailing professors actually worth it and look good on college application? (Cause I know basically you help with routine and set up some stuff so does it really get a point doing so?) Also do you know any other activities (not too hard like national/international level or genius competition w/ research) that could make big impact? I know some of you would recommend top-tier activities but I'm not that smart :( so wanna ask if there are mid-level activities that still stand out??

Thank you!!