As a society we choose to let the excess wealth pile up into the hands of people that are investing to bring about their own utopia.

If we're stretching, we can talk about opportunity cost. But the people spending and creating the "bubble" don't have better opportunities. They're not nations that see a ROI on things like transportation infrastructure or literacy.

So unless the discussion is taken more broadly and higher taxes are on the table, there really isn't a cost or subsidy imo.