I’ll use numbers to illustrate the point. The numbers are rough, and not exact.
If you buy a house worth $1m and pay 2.4% interest that’s let’s say $24k a year, or $2,000 a month.
Now the interest rate jumps to 7.2%. Now if you bought a $1m house, you’d pay $6k a month.
Typically when rates rise like this, housing prices drop. But in order for the housing price to drop so much so that you’d be paying less than the $2,000 a month you’re paying now (i.e. getting a better deal) the house price would have to drop 68%, to $320,000.
Even in the most horrible market, a 68% drop is almost unheard of.
As for inflation, they say that we are poised for A 10-15% inflation rate, annually. That’s bad, but that just means that you’re really paying $2,300 a month, in current dollars, not $2,000.
So in short, no inflation would not wipe out the gains you get from getting an extremely low rate.
A different, yet related point is that your house may be “under water” or have negative equity. That is a big problem if you need to move/sell the house. So you’re stuck in the house, that’s the downside.
The upside is that you are paying less (monthly) than you would if you were tryingto buy the exact same house today.