the longer time spent in academia, the more you realise how its progression structure is a pyramid of economic struggle which functions to wean out the working class. this is probably obvious when thinking about higher education in places like the united states, where student debt after a typical undergraduate degree can be in excess of $150,000, however it may be less obvious in places like the u.k, where it is generally believed that university is accessible to all due to bodies like 'student finance england' etc. such bodies are probably the reason for the largest diversity of students in terms of their socio-economic background at undergraduate level, as this is the only time government support is available to pursue higher education in the form of maintence loans and/or grants (although little government and/or institutional support exists for students with dependents). progressing to a masters degree in the majority of cases however is impossible without securing highly competetive scholarships which would act to cover 100% of your fees and maintence costs. in reality the majority of available scholarships don't even cover 100% of the costs, so you would have to make up the shortfall yourself, and often these scholarships are super hard to come by unless they're backed by a large corporation, whose interests are seldom aligned with academia. acquiring bank loans for further education is often not possible depending on your socio-economic background either, and frankly the interest rates on a bank loan would make people think twice about pursuing a masters degree. doctorates are a similar story; unless you can secure highly competitive funding there is almost no chance you'll find a position. its unlikely a potential supervisor just has a huge pot of money to hire a phd student for 3-4 years. once again, the expected long working hours during a masters and a phd also make it difficult for people with dependents (although part time study options are available). short-term (1-2 year) international job positions such as postdocs (which are essential if you want to pursue a career in academia) then also present significant barriers for working class people. you may be hired for a position on the other side of the world, and may need to come up with thousands of pounds/dollars to be able to relocate yourself and find suitable accomodation for yourself and any family, and then pay the costs all over again to relocate yourself when your position comes to an end.