I understand the analogy. But my argument still stands. It's about fear and the fear of what you might lose if you support the elimination of student debt.
Everything has a cost. Which is something we on the left tend to be bad at being honest about
That's not what the analogy means. It means that everybody loses if we are unwilling to progress, not just racial minorities.
There are benefits to society as a whole if we can lower the financial burden (eliminating student debt) of young people entering the work force, from higher birth rates, to buying houses, putting money back into the economy, starting small businesses (which create more jobs), and more... This is what economists say, the cost is a net positive.
However, if you go to a Twitter thread debating erasing student debt, the number one argument against it you will hear is "I had to pay my debt, so why shouldn't everyone else?" or "I've paid my debt, now I have to pay everyone else's?" - This is the swimming pool analogy.
So what's going on here? We know from studies that people tend to sort themselves into groups (or identities) naturally without any provocation. (The left didn't invent identity, or identity politics). We also know that people are willing to help those of similar identity, and will disadvantage those who are outside their identity, Sometimes even at a cost to themselves (the swimming pool example).
The thought of helping those outside of their identity is a deal killer. The ploy of modern (alt) right wing politics is to highlight divisions, create fear between them, and then cut social programs that help the victims of their racist society.
But again,
the answer isn't to homogenize culture. We are going to belong to different identity groups no matter what we do. That is reality. It's not racist to acknowledge that as you state. It's fascist to try and change that. The solution is to create a culture where people's differences are celebrated, and build an inclusive society where we can implement progressive programs that benefit society as a whole, and in turn provide net benefit for everyone.
I want to emphasize that different Identities within a society is inevitable, and makes for a more robust dynamic culture. It is a strength. The right uses it against society to achieve its goals of lowering taxes on the wealthy, and to maintain a social hierarchy where their identity group remains at the top. (John Birch society)
When you say "everything comes at a cost" - be aware that there are policies that are a net positive. Enabling society as a whole is a positive. Burdening groups within our society is a net negative and has known costs.