I'm in your camp, but I am also very cynical. I think your reasoning assumes they care if you do/don't vote. They know that they have an army of rubes (both Republicans and Democrats) who will "vote blue no matter who" or whatever the conservative equivalent is. In the last 8 years I have seen many very intelligent people compromise on their supposed values because to do otherwise would be an existential crisis. I don't know how you break through that.
House races can be surprisingly close. Either in the primary or the general depending on if it's a "safe" seat or not. The one thing they really care about is being re-elected. They will notice, even if they win a tough primary for a safe district they're not going to forget it. And if you manage to unseat enough of them then the message is even louder to the rest.
This is the way the game was meant to be played. Just apathetically voting for what's in front of you was something the parties invented to make it seem like there's no way to make change.
When Trump won PA he won. The one state where we know people stayed home because of Gaza was Michigan and it would have caused a win for Trump if they had gotten to that point. But Michigan effectively didn't even get a chance to count because Pennsylvania's electoral votes put Trump over the line on their own.
Realistically they had to defend PA. Georgia and North Carolina were always a long shot and the only way the Democrats could survive losing Pennsylvania. PA landed Trump his 270th EC vote.
It's electoral vote math. PA filled the exact amount they needed. None of the actual swing states mattered if PA went red. And I say actual swing states because Georgia, North Carolina, and Florida were only swing states on entertainment outlets cosplaying as news. On the inverse, the Democrats didn't have a path to victory without Pennsylvania. There just weren't enough other Electoral College votes available.
That, and voter suppression, voter-roll purges, selective closure of polling places, intimidation, and of course lying media expecting perfection of Democrats and giving a free pass to fascists.
Unless your platform is anti-abortion, anti-tax, pro-jesus then that would just split the vote between you and the DNC candidate, ensuring the GOP wins and doing more harm than good.