None of the parties can promise to reverse Brexit because it isn't within their power to do so.
But your reasoning can also be applied to my not wanting to vote Labour.
I simply don't believe anything they have to say on the subject of women's rights.
We have seen this before, with Brexit. In 2017 Labour tried to court both leavers and remainers and said just enough to get remainers to vote tactically for them, whilst not actually promising to do anything to lessen the fallout from Brexit, other than vague claims that they would "get a better deal".
Of course, those of us who understood how the EU actually works knew that the only way to get a better deal was to agree to continued free movement. Of course Labour weren't going to admit to that, because it would have required them to come off the fence and say to leavers, "Sorry, but we can't control EU immigration AND have economic prosperity, and we think economic prosperity is more important because it pays for stuff like schools and the NHS."
So they said just enough to persuade remainers to vote for them, and no more.
Then once the election was over, it was all, "everyone who voted Labour was part of the 80% who voted to get Brexit done", and so despite Gina Miller's landmark judicial review case, Labour voted to give Theresa May carte blanche to trigger Article 50 without setting any parameters whatsoever, then sat back and did fuck all for two years, and then when she came back with her deal which was the entirely predictable result of the red lines she had set, said, "Wah wah wah, we don't liiiiiike it!" when asked to vote in favour of it in Parliament. But it was too bloody late for that, we were staring down the barrel of no deal.
I vote in a constituency where it is the Lib Dems, and not Labour, who have the best chance of ousting the Tories, so I voted Lib Dem. If Labour had had the best chance of beating the Tories, I would have voted Labour. And given what happened afterwards, I am glad I didn't vote Labour, because no one can accuse me of having voted to get Brexit done.
But this is why I don't trust any of these incoherent mumblings from Labour about protecting women's rights.
Have they explained what they think a woman is, other than the fact that only 0.1% of them have penises?
No.
Have they apologised for the treatment of Rosie Duffield and dealt with those within the party who have bullied her relentlessly?
No.
Has David Lammy apologised for calling women "dinosaurs who hoard rights"?
No.
Has Lisa Nandy said, "I admit that I was completely wrong about the prison thing. I really hadn't thought that though."
No.
Has Keir Starmer said Labour won't introduce self ID?
No. He's said it's "not a priority".
This is Brexit all over again. They're making carefully crafted, plausibly deniable comments about protecting women's rights and self ID not being a priority, in order to persuade women who are concerned about this issue that Labour aren't completely batshit, that they take women's concerns seriously, and that it's OK to vote for them.
Then when they get into power it'll be full steam ahead on self ID and "if you voted Labour, you voted for this".
As for other issues, I'm afraid I just don't see them as a serious party at the moment so I don't rate their chances of magically turning the country around. The vast majority of senior Labour MPs were elected post 2010 and have zero experience of being in government. (That in itself is an argument against the first past the post system and in favour of PR and pretty much permanent coalitions. The current system means that you get a decade or more of one party which remains in power until everything is shit and people vote for change, and then they are replaced by a new crop of people who largely have no government experience.) Obviously their lack of experience isn't a reason not to elect them, and perhaps they will get into power and fix everything. Perhaps their legacy will be halting the cost of living crisis and saving the NHS. Perhaps they will even manage to get us back into the EU, against all the odds. But something tells me that the people who keep insisting that women can have penises are not the heroes and heroines we need right now, and they are likely to be a disappointment all round.