Voters can hold elected officials accountable by not re-electing politicians, not donating to them, and supporting candidates that will better represent them.
The problem is that most citizens are not civically knowledgeable or engaged which is why we continue to have to choose the lesser of two evils that are often the same in policy.
I do admit that this is more difficult for Presidential elections, but certainly this can be effective at the state and local level and arguably could be used effectively within Congress if done right. In fact, we might be seeing some of that begin to happen in states like Maine given the response Graham Platner has already received. Kat Abughazaleh is another example. She's a progressive who is taking a somewhat novel approach to her campaign in Chicago. And of course you have Zohran Mamdani in NYC mayoral race.
https://en.wikipedia.org/wiki/Graham_Platner
That's equally as useful as saying jaywalking and mass murder are both crimes
but they're both the same (rolls eyes)