There is a lot of “invisible” work that party orgs do. If you want to see why big names and attention alone don’t work, look at the Green Party. They have name recognition, ballot access and even get a bit of the vote each presidential election. What they’re missing is the “ground game” that gives the presence in nearly every race in every precinct, and the local engagement to actually win an appreciable chunk of elections every year (not just the presidential years).