Banks are now offering only 5% deposit for mortgages (Nationwide for instance). Take a starter home/flat in the north, say £200k (yes you wont get a fancy area but you have to start somewhere), thats 10k deposit. With the LISA, 2 people saving 4k each and topped up by the government can have 10k is a year. For kids still living at home and working full time that should be pretty easy to do, if they cant then they really dont have much chance of maintaining a house and paying the bills.
I appreciate that many kids after university for instance, dont want to go back home, but thats the sensible thing to do, even if it means taking a lower wage and its not their dream job.
The real issue is for those who can't live at home due to family issues/brought up in care. Those circumstances I agree would make it very tough.