This is not my personal opinion, I know Gen Z men who voted for Harris. But the voter demographics really speak for themselves, and maybe now people will look at the radicalization of young men as a serious (but solvable) issue.
It’s the economy. Look at the numbers for voters without a college degree, rural voters, and lower income voters. Trump won all of these groups. In the WaPo exit polls the issues are included, not just the demographics. For voters who think the economy is the most importantly issue and for voters who think the US economy is doing badly: Trump dominated.
The Democrats continue to fail at shedding their reputation for being out of touch with working class Americans. The only income bracket that Harris won was the $100,000+ group. This tells us that the Democrats are an upper middle class and upper class party.