To give some more specific examples:

Liberal voters: We pay more for healthcare than anyone else! Can you use our money for Medicare for All?

Politicians:

Voters: Why have we been blockading Cuba since fucking 1962? Make it stop!!

Politicians:

Voters: Scientist are warning about climate change!! We need to take drastic measures!

Politicians:

Voters: ICE is killing people and racially profiling! It's a danger to us all and must be abolished!!

Politicians:

Voters: Stop killing brown people with our tax dollars! Pull support away from Israel!!

Politicians:

Leftists: I can no longer support the Democratic Party

Liberal voters:

My point stands. D taking your vote and your donation while not doing anything is still less bad than R actively stubbing you with his knife.

So vote blue no matter who?

And for whom both parties work

Because the ones who refuse to are the corporatocrats, corpo “centrists”

Women's Suffrage was won without voting. Civil Rights was won with turnout among black people between 25% and 7% per state. It's not voting that moves things in the right direction.

And remember. Both the Ds and the Rs had to give ground to prevent the civil rights movement from getting out of their control. As soon as they had it appeased, both the Ds and Rs co-architected the war on drugs and heavy "anti-crime" work to criminalize black people. It's not a coincidence that prison population skyrocketed immediately after the civil rights era, targeted black people primarily, and haven't come down since regardless of who is in office.

Corpos aren't loosing, they are growing in power with rising wealth inequality. Money is power. Think of every dollar they have at their disposal as a tiny little soldier running around and whispering in people's ears. They are backed by itty bitty generals who are the smartest people on the planet, paid the highest wages to come up with the best most foolprofest brainwash / propaganda / public relation / talking points / advertising imaginable to manipulate people. You think you have a chance against that??? Is this fucking Sparta, three hundred vs one billion?

Even more money can be poured into elections now. You don't even have time to protest because you don't have the money. Any they long figured out how to game protests to make them harmless anyway.

Look at how the dems gamed the system to prevent a Sanders presidency. Not even a lukewarm social democrat could they allow against Trump. And Obama, the corporatist of dem all is still being worshiped. Every time I see posts blaming this small faction or the other for the second Trump presidency I cringe. It's like you're in a prison for your mind. The election shouldn't even have been close. No, Trump should have been in jail. Put the blame where it fucking belongs.

YOU DO NOT LIVE IN A DEMOCRACY. People do not even know what is real and what isn't any more. The only good thing is that their laws and state violence are illegitimate, and you are under no moral obligation to follow them anymore, except self preservation. Zeroth law of robotics is in full effect. Civil disobedience or whatever. Organize locally and offline.

PS: Sorry for the rant. Sucks to live in interesting times.

Then the posts aren't encouraging them to change any behavior. This premise only works if you have partisan voters deciding not to vote because of the Both-Sidesism.

If it is the default case that a party already does not have the any votes of the largest mass of voters, then the parties should focus on gaining their support.

But also: more libertarians protested the GOP over Both-Sidesism than leftists, so technically it still had a net benefit effect for Harris. Which further demonstrates how flawed the whole premise is.

Its from more people voting on the right than people voting on the left.

If we restrict the answer to just electoralism, I'd say it's because more people are voting greater evil than lesser evil and OP's image explains why.

It actually does, even considering that. That's just how bad the greater evil party is. There's a lot of space for the lesser evil party in their wake. But yes it does get worse overall either way. That's why while voting is important, you really should be doing something beyond that as well, if you really care. And if you really care enough to do something beyond that, then merely voting should be trivial for you to manage.