Majoritarian democratic systems require group coordination to achieve desires outcomes. Political parties are just a vehicle for doing that. If you care about outcomes, you should have some party identity, because that facilitates compromising less important goals for more important ones to achieve a coalition that can carry a majority.

I agree parties shouldn’t be so ideologically rigid, and for the most part they aren’t. Jamie Dimon and AOC are both in the same party, as are Marco Rubio and Tulsi Gabbard. People who refuse to work within a party unless the party agrees on every issue are simply not interested in outcomes. That’s fine too!