I don't see the relevance in this discussion
You rarely see the relevance in anything that doesn't fit your agenda, that doesn't change it
You're focusing on the voting choice of people who actually voted by age group.
Votes are counted on absolute numbers, so turnout matters.
If you have two groups of 10,000 voters, and their headline voting rates (split for simplicity) are as follows.
Group A.
Labour 90%
Tory 10%
Group B.
Tory 90%
Labour 10%
If turnout is identical in both groups, the election will be a dead heat.
If, however, group A has a 50% turnout, and group B has 100% turnout, the overall results look very different.
Group A
Labour 4,500
Conservative 500
Group B
Tory 9,000
Labour 1,000
So now, the Tories win by 5,000 votes, or near enough 60% to 40%
This is the key issue, young working people who actually vote do tend to support labour, at least at the last election, but barely 40% of them actually vote. This contrasts with voting rates nudging 90% in the elderly.
Working people, if they all votes, could outvote the retired, but they don't. The system, in that respect, isn't failing, it's working as intended.