From what I understand, it's universally accepted that a mortgage is often worth the debt and interest paid due to property appreciation over time. However, obviously this assumption is based on considerable appreciation (which has been observable throughout recent history).

With the knowledge that rent is cheaper than a mortgage payment, with no debt interest being paid, the short term seems to always favor renting unless there is enormous appreciation.

For the long term comparison, does anyone know what percentage of home appreciation is required to outperform a renter who invests the difference of price interest?

Example:

John purchases a $300,000 home with a 6% down payment ($18,000). He has a interest rate of 3.6%. It takes him 20 years to pay off the mortgage entirely, and winds up paying a good amount of interest (not sure how to do the math, some help here would be appreciated!).

Claire rents a home and pays $200 less monthly than John, and pays no interest. She also avoids liability for appliances, upkeep, property taxes, etc. At the exact same time as John, she invests the down payment amount ($18000) and the $200 per month she saves as a renter, into the stock market with a portfolio that returns 6% annually.

How much would John's home need to appreciate to outperform Claire's investment decision to rent instead of buy?

----I know this is an intimidating amount of math, thank you so much for whoever is able to help me calculate this!