Rudimentary example using real numbers from my life:
Rent is $4200 per month.
Buying a home at today's local prices and rates: $8500+ monthly housing payment. This includes a $250,000 down payment. House is $1,250,000 in an area with 1.9% total property taxes.
The $4300 monthly difference and the $250,000 down payment instead gets invested in an ETF. In 30 years, conservatively (assuming 7% annual growth) I'll have more money than that house will ever be worth in my or my kids lifetimes. I'll have somewhere around $7.1 million dollars. The house, historically, can be expected to appreciate 3% per year over time. In 30 years, it would be worth something like $3.1M.
This is how renters "build wealth" while renting. The stock market has ALWAYS outperformed the housing market.
This works when rents are lower than mortgage payments, but ALSO works when you take ANY extra you would have had to set aside for maintenance, property taxes, and insurance and invest it every month while continuing to pay a fixed monthly rent.