I absolutely agree that this entrenched two-party system is a clear issue that needs to be resolved if the US is to become a real functioning democracy. But also woe to noting that there are other parties in the race also; they just don’t have popular support.
Two parties is the mathematical equilibrium of every first-past-the-post system.
Only way to have more parties is to adopt something like a proportional parliamentary system. Which will never happen because you'd have to change the constitution.
There is a presidential election coming up. That is the test that actually matters.
Kamala Harris will either win it or she won't. If she wins then she was good enough to win. If she doesn't win then she wasn't good enough to win.