Arguably, people who use laundromats are subsidizing those who own their own washer and dryer too, it’s just a pretty small subsidy because a very small amount of our income goes toward washing clothes.
The argument that renters subsidize homeowners is based on imputed rent, and you could make a similar argument for “imputed clothes-cleaning”.
Imagine two people who both work the same job and live in the same model house side by side. They make the same income from working. One of them owns the house, and the other rents it. The one who doesn’t own the house instead owns some other investments that provide an amount of money equal to their rent payments every year.
To throw some numbers at it, let’s say they make $50k a year working, the houses cost $100k, rent/other investment income is $1k a month.
From every vantage point except homeownership, these two people are the same. Same net worth, same W2 income, and the investment income balances out the rent.
But the owner gets taxed on $50k of income, while the renter gets taxed on $50k+$12k of income.
Sure, the owner pays for upkeep and property taxes. But the argument goes that those must be lower than the rent paid by the renter because otherwise the landlord wouldn’t keep renting the property. In the long term and on average, that’s almost always true.
As you point out, this applies to anything that can be owned or rented. And it mostly comes down to economic efficiency. In most cases, it’s more efficient to own an asset that provides some use that you need unless you need it infrequently enough to be worth the premium that you’ll pay to rent someone else’s. Since most people want to live in a house all the time and not just occasionally, owning a house is (usually) more efficient than renting it.
Which just circles us back to the point of the thread, which is that if you’re poor, you often can’t afford to own all the things that you’d use regularly because you don’t have the money, so you’re forced into the economically inefficient rental market where you pay higher taxes, higher transaction costs, and more of someone’s profit margin.