This is actually a pretty good question for initiating some discussions. I think the hardest university course to get into is relative at the end of the day. It is like when you compare a golf ball to an atom, the golf ball by comparison will be inevitably much bigger, but if you compare the same golf ball to a water melon, suddenly it seems very miniscule. The point I am trying to make is that the difficulty of the university course is determined by a lot of factors, including societal perceptions of certain courses(stereotypes/expectations) etc, however the three main factors I think are the following:
1)The university that you want to get into-obviously getting into a course in Cambridge University is much harder to get into the same course in USYD/UNSW, for the simple reason of supply and demand-the higher the demand, the more competitive it is to fight for a place, and hence the 'harder' it is to get into the course
2)
The 'barriers' that has been established to select individuals into the university course-this includes assumed knowledge/prerequisites for university courses-such as to do a maths degree-2 unit/3 unit is assumed knowledge, prerequisites such as post graduate programs requires you to have an undergraduate degree, the number of exams and other entry considerations that must be taken and the difficulty of the exam to get into the course-for example, for Medicine, there is the competitive UMAT and often interview as well as high ATAR requirement, for getting into a visual arts/music degree-you often need to do an audition, present a portfolio and interview.
3)Individual circumstances-this is the last, but arguably the most important factor of all-the reason being obviously if the individual has economic disadvantage, has excessive familial/work responsibilities, has physical/mental disabilities/chronic, long term illness, has less access to educational resources, is not passionate about the university course they get into and not genuinely sure why they want to do it-then these uncertainties and features can certainly make particular university course more difficult to get into than others.
I have deliberately chosen to put inverted commas around 'barriers' and 'harder' in my first two points-because I am a passionate believer that additional entry requirements are only 'barriers' if the individual perceive them to be. If the individual is passionate enough to enter into a particular course, then they will transform these barriers into opportunities and use these 'barriers' as motivation to get into the course-no matter how long it may take. Again, a university may be 'harder' to get into-base on the individual's lack of determination/resolution to sit the exams and get in. Ultimately, if individuals are genuinely passionate about the university course they want to get into, although the nature of entry requirements may be difficult, they will not be deterred by the 'barriers' that are in their way and find a way to get in
