I don't necessarily disagree C8H mainly because, as you said Their teachers were not always aware either.
That is because of long term funding changes. Not the teacher's fault. That is something everyone should be protesting about.
Nonetheless, the information is 'out there' in a format many students say they prefer. There is so much of it available and yes, it would be easy to drown in it, but honestly, the UCAS system really does set it all out in an easy to follow format. Yes, there is a lot of info, but if you are applying for a degree you really should be giving it a lot of thought, especially these days with the fees.
For almost 20 years, every single year I've been there, sat with a 17 year old who is the first in their family to consider going to university. Some with little or no support. They were usually the ones who did most research, read every page on the UCAS site and could usually teach me a new thing about the application process.
Once the decision to apply for something has been made the process really is supportive and informative. Support to make that decision is a bit different, but as UCAS have reps who go out to schools, conventions etc, they do pretty well there too.
Add to that Open Days, in FE colleges and Unis, the centralised Fairs and various Youth Programmes in less privileged areas and there is a lot of support for the decision making too!
I am NOT saying it is easy, I AM saying that if a student is determined to go then there is a lot of information to help them make the right choices.