I wrote up a long reply that failed to post, but the TL;DR is that's not really the right way to look at it.
The cost of home ownership is the interest part of payments less home ownership costs plus home value appreciation vs. rental cost, then factor in the intangible personal value of home ownership vs. renting.
70% of a home's value in interest could be a bargain compared to rent over 30 years.
Edit: I just did some napkin math on my situation, and we'd need to have housing and land prices drop by 20% over the next 30 years and a major maintenance item every 1-2 years for us to lose out vs. renting. There's no way that's possible on that long a timeframe. Even if there's a catastrophic 75% market downturn, it will easily recover over 30 years at below-historical-average gains.