There is no philosophy, classics, Latin, Law, engineering, German, business studies, etc. There is no computer science course as there is no teacher
Many of those weren't available at A level my DDs GS (she had a CS teacher but he left, they did have German.). I don't think any of those are essential for any Oxbridge course, albeit for classics it would have to be the 4 year course. Some would be no advantage or even a disadvantage versus 'vanilla' subjects.
Having seen the process at first hand and a cousin who was successful in gaining a place (from a school where they get at least 10 in a yr...) I would not recommend people apply.
Having seen the process at first hand I would absolutely recommend applying, so long as the applicant does it with a 'nothing ventured, nothing gained' mindset, and accepts that the statistics mean they likeliest won't get a place even if they're good.
And maybe if they find any of the steps of the process truly offputting, they should be offput.
Write a PS (which they have to do anyway) - write about your interest in your subject. If you can't do that (SEN considerations aside) why are you even applying for uni courses in it anywhere?
Do an aptitude test, based on standard A level content plus maybe a bit of out-of-the-box thinking ability. Really not a big ask fo able students. If you can't deal with that test, exams will be a worse problem.
Interview - talk with a couple of knowledgeable strangers about your subject. Now, that part may be somewhat scary, but if it's terrifying then a system with a strong element of supervisions/tutorials may not be best for your character.