The gap between the rates on the 30 year treasury and the 30 year mortgage increased from ~1.5% to over 3% and getting worse, before QE4 was announced (and this was already pricing in some fed action). This indicates that investors stopped buying mortgage-backed securities which would have eventually resulted in home buying activity stopping and a housing market crash. I don’t think any bailout for restaurants and bars or mortgage/rent holiday would have helped with this. I’m not saying such stimulus isn’t necessary, but it doesn’t replace fed policy.