I suspect you're being ironic there (in bold)
I spent a lot of time trawling through threads on the TSR Oxbridge forum a few months ago and some of the attitudes towards the concept display a wide range of emotions, including a lot of negative ones!
To the OP: don't get so caught up in the Oxbridge or RG obsession that you lose all perspective on things. Research into courses you think will be an interesting and manageable challenge for you. Have a look around on uni websites and even better, go to some of their open days. You may be surprised to find that when you start visiting places in person, you don't actually like some of the "good" universities and prefer some of the supposedly "weak" universities. Maybe not, but at least you'll be more informed.
There's nothing wrong with an Oxbridge ambition per se, but I think you need to analyse it to see if it holds up under scrutiny. A lot of people's ambition to go there is based largely on the Oxbridge brand name. Why do
you want to go there? I know the standard answer is something like, "because of the fantastic teaching and the kudos," but it's worth thinking beyond that.
I can't really comment too much on the value of the kudos, since I don't really know enough about that side of it, but the teaching aspect is something that you can evaluate for yourself. In respect of the courses on offer there, would you really be happy studying one of them? What that question is really asking is - admittedly this perhaps does depend on the subject, but just using a Humanities subject as an example - are you going to be happy churning out 2-3 essays each week on this subject? Are you going to thrive being among small groups of highly capable students debating the ins and outs of the subject? Are you going to be comfortable sitting down with the lecturers for one-to-one tutorials where you need to present your proposed arguments that you intend to use in your essays? Are you going to enjoy the rigid approach to the subject that they adopt?
I appreciate that studying at an RG uni isn't as gruelling, but you still need to think beyond the name and about whether any of them are really the right place for you. Imo, people who universally dismiss all unis outside of Oxbridge and the RG and their students are highlighting their own insecurities and narrow-mindedness more than any weaknesses of the targets of their attack.