30 year mortgage is founded partly on the idea that your house will be worth more in the future when you sell it. That you can lock in a lower price now. Number cannot always go up. We are at the top of the carbon pulse. Financialization has taken us far from the material baseline of the rock we are flying through space on. Debt will only get us so far. For this and many other reasons, why would you believe a house "…
inflation disagrees with your premise, there is no reason why number can't always go up, there are plenty of countries that prove otherwise.
Physics and reality do not. Once the number gets big enough it loses all practical value. Humans are not really built to reason about very large numbers. At some point you reach Zimbabwean inflation and your currency loses all value because everyone is paid in the trillions. Then you reset your currency back to lower numbers because that's what humans and their systems can handle.
So, no, the number cannot always go up. There is a practical ceiling beyond which numbers lose meaning and value.