uni oxford or cambridge

I'd recommend you to take a look at the details of each university. Delve into the details of the course modules, the exam structure, the professors, the tutorial /supervision structures etc.
I chose Cambridge because it just resonated with me. I did have a period where I considered Oxford, however, it was very brief. It was always Cambridge for me.
Furthermore, take a look at the colleges. This is something you'll have to do anyways later on if you do apply. Perhaps a college will stand out to you.
I'd say with grades and subjects like yours, you'll have a good chance at both (given that you also have a great ps, admission test score and interview performance ofc). I've heard somewhere that Oxford admits people based on a 'shortlisting' method, while Cambridge works by 'rejecting people below the threshold '. See which one you feel more comfortable with. Are there any alumni you particularly look up to? Which extra curriculars are you into and which uni would suit your activities? If you're totally fine with both, then it's just a matter of looking for something that can help you make a firm decision. Even if it's something niche like accomodation style etc.
Do some research! The more research you do, the more clearer it will become. Watch YouTube videos of each uni, see which uni is researching into areas that you have a keen interest in. I believe you'll definitely have a definitive answer then.
If it really comes down to it, just choose. Like you said, both are amazing in all departments so what do you have to lose?

Standard question - but how do I pick oxford ro cambridge? They're both top of leagues consistently, both very pretty and very competitive. How do you tell which is more 'you'? Since you can only apply to one how did you pick? Also I want to do medicine so the course will be the same practically and their structures both look good. Idk which one to choose next year. Also have top gsce grades and 4 stem subjects so I could be 'competitive' for either.
Any help would be appreciated

Standard question - but how do I pick oxford ro cambridge? They're both top of leagues consistently, both very pretty and very competitive. How do you tell which is more 'you'? Since you can only apply to one how did you pick? Also I want to do medicine so the course will be the same practically and their structures both look good. Idk which one to choose next year. Also have top gsce grades and 4 stem subjects so I could be 'competitive' for either.
Any help would be appreciated