Yes, it moves the problem until after you’re dead, and it moves the problem into the future when the value of your securities will have substantially grown, thereby reducing the real cost of your house. Both of those things are good!
If I borrow against the securities, I get cash. I use that cash. I now have zero cash (again).
You have zero cash plus a property asset. The value of that asset will grow as well. Both the asset and your securities are, in fact, growing in value at an interest rate that’s greater than the interest you’re paying on the loan.
So you’re getting free money. It doesn’t come from nowhere, of course; it comes from the future people who buy your securities. They essentially paid you in the past to buy a house, and they’ll be paid to have done so by people who need to enter the securities market later on (by buying securities.)