Let’s imagine what it would be like if we did not have political parties.
First of all, when voters looked at the ballot, they would see the names of candidates, without a party label. Therefore, in order to have a preference, the voter would have to do some research on all the candidates before going into the booth.  This would prevent zombie voters voting for a party that doesn’t actually represent what the party label used to represent.
Political parties should not be in control of the nomination process, because when they are, real choices are eliminated by the oligarchs prior to the election.  Consider the fact the Kamala Harris is the nominee for the Democrat Party, even though no one was given the opportunity to vote for her or not, and the Democrat primary in 2024 was a sham in the way that they changed their rules to keep RFK Jr from winning.  They even invented a new rule that if RFK Jr won the first primary in New Hampshire, where he was leading, his votes would all go to Biden instead.  I kid you not.  In 2016 Bernie Sanders supporters were told by the courts that a political party is a private corporation and it can pick the nominee in “smoke filled backrooms” without consulting voters, at all. 
Even though political parties are private corporations that don’t have to give a shit about democracy, they still run sham primaries at great expense to local governments, to promote the illusion of democracy.  Instead of this, every candidate should have to do what every independent candidate has to do to get on the ballot and that is: collect enough signatures per the state guidelines. Furthermore, if only volunteers are allowed to collect signatures, that would help get money out of politics, at least for the nomination process.
Assuming that several candidates would qualify for the ballot if all candidates ran as independents, Ranked Choice Voting (RCV) could be implemented on general election day. RCV is like an automatic run-off and the winner is the candidate who is the first and/or second choice (or third) of most voters.  With RCV, there is no threat of a “spoiler” and so people don’t feel forced to vote for the candidate more likely to win than the candidate they actually prefer. In states where RCV is used, including New York city, the electronic voting machines have to use open source software, to eliminate electronic election fraud.
Because citizens have the right to form associations, political parties would still exist and they could publicly endorse candidates and organize volunteers to collect signatures.  They just would have an out-sized role in controlling the nomination process.
Imagine then that none of our representatives have an R or a D (or L, G, or I) after their names when they appear on television. Imagine a Congress that is not divided into the majority and minority parties. Group think wouldn’t prevail quite so much.
I believe that the party system also gave us Donald Trump as the only false alternative to the powerful party machine. The system we have encourages divisiveness and tribalism. If you can think of one good thing that parties contribute to the political system (that I haven’t already proved false here), let me know.
I'm not a legal scholar, but I believe that disempowering political parties would have to be done through state ballot access laws.  Maybe New Hampshire could be the first state to experiment with eliminating political parties from the nomination process.