It's not even just that. Having experience of just how easily Housing Benefit or Tax Credits can suddenly decide to suspend your payment because, well, pretty much because they feel like it (when I got made redundant they suspended my Housing Benefit, which I was already getting, for a few weeks while they processed the fact that I'd told them
I'd lost my job ) Universal Credit scares the bejesus out of me. The way it is now, because I get HB once a month, Child Benefit once a month at a different time, Tax Credits once a week and Income Support fortnightly, if one of the buggers makes a cockup and leaves my claim sitting in an in-tray for a couple of weeks, I know I'll have some other income source coming shortly and might be able to stretch things to bridge the gap. Under UC that won't be an option. I can see people being regularly late with their rent, getting into overdrafts, getting evicted. It's nothing to do with not being able to budget. It's to do with not having the safety net of a few grands' savings to cover your rent in an emergency.