I am not sure I agree. DS has been a bit ambitious, and made his decision entirely on the courses offered on the basis that his AS results were disappointing but he did not want to take a gap year. We were not aware at the time but he has effectively applied for five of the top six ranked Unis for his subject. Oxbridge, 2x London, Bristol and Warwick. The thinking was that he would either go to one of these or reapply with A2 results and an AS resit, thus pitching his application more accurately.
The good news is that he has received a very achievable offer (thank you admissions officer) technically from the lowest ranked University. It is an offer he may well end up firming even if he gets offers elsewhere, simply because University, like schools, is about life experience and personal growth as well as results and rankings.
A friend's daughter at THE super-selective London girls indie refused to apply to Oxford. She had done a pushy prep and a pushy secondary, and wanted the chance to take her foot off the pedal for a while. She's bright and could well end up more employable for being better rounded and not having stuck to the same small group all her life. My friend is delighted, though other parents were apparently quite shocked.
Another friend is delighted that her son has just started at Northumbria. THE place to go for product design.
Post grad might be different, but the idea that University decisions would be made simply because they are considered Tier 1 or Tier 2 is depressing.