I think the need going into Autumn / Winter was something simple and fast to head off fear.
Targeting is great in theory but needs careful design to avoid a level of complexity that will be beyond some people (particularly the most vulnerable, sadly) and other unintended consequences.
Perhaps not in this case, but sometimes a universal solution is not THAT much more expensive as the admin is so much simpler. After all, although my energy company knows where I live and how much power I use, it has no idea about my household, my income or my savings...