I think many people place an over emphasis on policy when it comes to voting intention.
I'd argue a far more important driver is that of credibility.
A party can nail their policies and still not gain traction if there is a lack of belief in their ability to govern effectively because they do not present as a credible force.
The Lib Dem's lost their credibility as a result of joining the coalition in spite of their policies remaining broadly static between the height of their success and current nadir.
Labours performance at the last GE wasn't solely the result of pie in the sky promises, a significant factor was Corbyn failing to make the case for himself as being a credible future prime minister.
Sturgeon lost huge swathes of support despite the hugely motivating and binding force of Scottish nationalism because tied herself to a policy that undermined her gravitas, reputation and questioned her intellectual integrity.
Regardless of whether this is a major issue for most voters, it's important because irrespective of labours policies going into the GE, this issue more than any other has the potential to undermine the credibility of every single Labour MP (so a large majority) whose gone on record denying basic biology.
How to you put Lammy for example on Question Time when you know damn well he's going to get asked if he thinks women are rights hoarding dinosaurs because they don't want a male rapist in a female prison?
As the recent JHB interview demonstrated, all the policy positives are utterly lost in face of the fractured, halting and stumbling responses to the question of what is a woman - and that becomes the story every single time.
In addition as has already been posted people misunderstand what Labour need to achieve here.
It's not just about increasing the national votes. It's about winning in some very specific constituencies and the margins for doing so can be very tight indeed.
To do that you need to have a very good grasp on the swing voters within those specific seats that you need to win over and generally speaking this demographic isn't the younger/woke population.