Infrastructure spending would put an end to QE and the increasing wealth inequality.
I'm in the UK and we're increasing spending on 5G, but lots just goes elsewhere. Our constrution sector has limited capacity, and has less now we have EU staff leaving (and not arriving), so any extra spending will just lead to price inflation (and wages for already well paid people). Actually getting new people (and companies) in to these sectors is hard, not as sexy, and as a result doesn't seem to happen.
The US may be different, but there are few really easy answers in economics. Almost everything has second order effects that you might not like! That said, having been to the US a lot, there is a lot of infrastructure that does need attention...