Hi there - thanks for sharing your profile!
I think the question of whether or not to retake the GMAT depends on a few things...
1. Other academic credentials - Your GPA seems strong and you have exposure to Finance already so the GMAT seems slightly less important in your case. I think schools will believe that you can handle the coursework of an MBA program.
2. Your target schools - The median GMAT for LBS is 710 and it's 704 for INSEAD, so your 700 is pretty darn close to those. However a score above the median, like a 720/730, would help in that you'd be increasing the school's median (which matters for rankings)
3. Your work experience - with experience in strategy consulting and PE, you likely have pretty top-notch analytical and quant skills, so again, I'm less concerned about a low GMAT, especially the Quant score, in your case. You could instead choose to highlight these skills on things like your resume and perhaps your recommendations.
4. Practice scores - were you scoring any higher on practice tests? If you feel like you are "leaving some points on the table" then it might be worth retaking. There's no harm in trying again. Or do you feel like you scored pretty close to your max?
Also, where you're applying from might matter too - are you Swiss? Do you have work experience in different countries? This might give you a slight edge as schools are always looking for diverse classes.
Overall, I'd say a retake is not necessary, but will depend on the answers to some of these questions and where you feel your time can best be spent. Keep us posted on what you decide and let us know if we can help!