Is your organization focused only on general elections, or on primaries as well? I couldn't find any information about primary elections on your site, even though many of the most consequential decisions are made then, when voter turnout is at its lowest.
As a non-Republican, non-Democrat, when I voted in the last primary, there was exactly one referendum on my ballot, and nothing else.
I was also the only person on the nonpartisan register at that time of the morning. They had to crack open the shrink-wrap on the ballots just for me. I imagine that not many other people would bother to drag themselves in to the polling place for that one issue, were they not also choosing candidates for one party or the other.
In many places, the support of a recognized party dramatically lowers the requirements for getting on the ballot. In my state, by as much as a factor of 3:
https://ballotpedia.org/Ballot_access_requirements_for_polit...