The issue is people are naive enough to think that just by voting for a democrat in a single election every 2/4 years is enough.
- Vote in local elections to ensure your state is run by people you support.
- Put pressure on politicians at all levels to support greater access to voting and more modern voting practices like rank choice voting.
- Create ballot measures in state that will allow for greater access to voting and more representation of other political parties.
Right now in the US, third party voting is neither adequate nor appropriate. It's why you see republicans backing green party candidates in certain states to help dilute democratic candidates.