No but unless you are daft enough to think your one little vote will bring in your local Labour MP and that MP will get Starmer the beige into power by one seat then my post is factually correct.
But if everyone had that attitude, then no one would bother to vote.
And the difference is, your voting intention isn't only one vote. It's bigger than that, particularly in this day and age.
Dozens, if not hundreds of people will see your post on here. Some might be feeling disillusioned, not sure about Starmer and thinking they might do a protest vote against him. And seeing your posts validates that idea and makes them more likely to not vote for him.
They might feel emboldened to tell their butcher, who tells his accountant, who posts it on Facebook and it's seen by hundreds of other, and so on...
It's exactly how Brexit happened. People who weren't sure about the EU, but knew deep down Brexit was a bad idea. Seeing messages online promoting Brexit, validates the idea that it's not a crazy, self-harming thing to do.
It's basic behavioural science, there's a good article on it here
https://compass.onlinelibrary.wiley.com/doi/10.1111/phc3.12658
If you lived in a log cabin and voted against Starmer out of protest that he's not Corbyny enough, I agree one isolated vote wouldn't make that much difference.
But being vocal about it with your peers, family, community and online, will have a far bigger net impact than that. Even if you, or they, don't realise it.