I look at the rental cost of a standard 1 bedroom flat in my part of London, and they want £1,200/month just in rent. It would be cheaper to get a mortgage, but I fail the "affordability" tests. Perhaps I am selfish, but I am not so desperate to move out to a relatively inferior property in which I possess no interest (since I will merely be renting) for that sum.
I don't believe I'll ever be able to afford a house, especially as wage growth allegedly stagnates and then seemingly declines past the age of 40. If these are my "peak earning" years, then I'm quite sad because at this rate I'll be trapped at home forever. It would be fine if rents were about the same as a mortgage: one could rent while saving.
At the moment though, renting while saving seems eminently unaffordable.