Your mortgage costs more because interest rates are low, making lending easy, making it easy to take out loans, meaning all the buyers can get bigger loans, meaning you have to bid more to win.
Second order effects. Interests rates are not low in a vacuum.
It is likely that because there's nowhere else to make good returns, there's a lot of money sloshing into stupid non-value-focused dotcoms that will dry up when interest rates go back up, creating competition for those dollars. Again, second order effects. You're not thinking economically if you're not thinking about those.