I would need to know what US state [if any] you are registerer to vote in to look up what your primary options were. And how you might have used it best to state an opinion.

In NJ:

We did have the uncommited option (got 9%, nearly the rest to Biden at the time, you could have also written in any other elegable person) However we also had a senate race:

In the democratic primary senator race, the results were (aprox) 9% for Lawrence Hamm 16% for Patricia Campos-Medina 75% for Andy Kim

If you want the US to be less involved with the Netanyahu government Kim was the worse of the three.

And this decision (ie who will be in the senate, driving laws) makes a huge difference in the party wide policy, that is the primary policy Biden (now Harris) is following… Since the president is inherently a centrist roll. (Ie center of those the people elect, this can of course shift left/right/up/down/ect with the electorate)

Is the system perfect no… (but posts on instant runnoff voting, or ranked choice will make the post a book, and they are not yet the system in play, last these systems would really only help reiterate the signal the primaries give… It would be still someone in the center of the electorate at the top… And if we are lucky more parties)