Just really to echo other responses here, whilst there is some truth in the OP, most of it is unfounded.
If you want to do a science/math based subject, and want to go to a top university, it MAY be necessary to have A Levels. But this varies with subject and institution, so always find out directly. Whilst A Levels are generally the surer route, plenty of people have managed it with Access, so there's no need to rule it out.
With arts/humanities subjects, there are very, very few subjects, and NO institutions that do not accept Access. Obviously, most languages will require an appropriate A Level, but that's essentially it. The only reason entrance might be considered more difficult is because many mature students don't have GCSEs representative of their ability, and can't prove this directly by gaining strong AS Level results. But universities are aware of this, and if the teacher reference is suitable, but they want further reassurance, will often request written work or an interview. I know numerous people who got into excellent universities despite having poor, or even no GCSE results.
Access in a lot of ways prepares students MORE for university. Whilst they might not have the same level of knowledge in a subject as A Level students, the style of learning is genrally closer to university learning.
For most people Access will be the cheaper, quicker path to university and provide exactly the same opportunities as A Levels.