What my DDs learnt was getting on with others, cooking for friends and being wholly responsible for food shopping, cleaning, bills, household admin, finding somewhere to live, studying abroad for a year with a great deal of admin and independence needed, and generally not having mum and dad around doing everything for them. They learn to navigate set backs without parents hovering.
Where could my DD have studied MFLs by staying at home? A car would be needed and the option would be Oxford or UCL. No public transport to either without driving to a bus stop or station. So it’s simply not the same as living away. It certainly was not 4 years of getting drunk and students are not all like this.
if dc live in a city with a suitable university commensurate with their academic standard and they want a local job, stay at home but it’s maturing at a different rate.
If dc don’t pay for accommodation, they certainly haven’t saved £60,000. They are almost certainly having a loan for the fees and the repayments are identical each month regardless of how much is borrowed. If you are going into a high earning profession, or want to, staying in a local university might well cut that option out.