My current house cost the same as my rent did (mortgage payment+taxes is equal to my rent I was paying). without taxes I would be saving about $400/mo. (I pay almost double in taxes and get a check cut to me yearly for the overpayment from escrow, but due to how taxes change my escrow plays it safe)

For example, say my rent was $2k/mo, thats $24k a year with no equity. Now say you pay $2k/mo in mortgage+taxes, thats $2k toward interest and your equity.

You can use that equity as an asset when taking out loans, or cash-out refinance it later to purchase more properties. (This is what most house flippers did).

Rent at fair market value for a house my size is already $2300/mo. In about 5 years it'll probably be ~$2600/mo(2% increase yearly). Thats $600 profit from renters who also pay my mortgage for me.

edit: clarification/cleaning it up