The great (but one time) unlocking

How much of US economic growth over the past few decades has been from one-time unlocking of previously frozen assets? I'm thinking home equity loans, unsecured borrowing, etc. And how much of Wall Street's income has been from finding this untrapped value and monetizing it? If we are largely unlocked (and we seem to be - we've borrowed against every asset I can think of, including future personal income all the way from the federal level to the personal by federal debt through credit cards), then growth from spending and growth from financial services income would seem to be over. Yikes.