I mean, if you like WUSTL’s flexible curriculum and are potentially interested in doing something in Business or Engineering, to me that is your answer right there.
I could be wrong, but I am feeling like you are maybe just hung up on Chicago having a higher ranking in US News and such. If it helps, I note my S24 applied to and is now enrolling at WUSTL in part because of that curriculum structure, and did not apply to Chicago at all. This is pretty common in his feederish HS, that only certain sorts of kids even apply to Chicago, because it is not at all the right choice for everyone.
And in fact, WUSTL is kinda famous/notorious for particularly favoring the high numbers kids. Indeed, back before test optional kinda rendered this data moot, WUSTL had one of the highest average SAT scores–in this version, it tied for #4 with Penn and Stanford, and was actually ahead of Princeton, Yale, Harvard, and others :
Now Chicago has the exact same reputation for favoring high numbers, and in fact Chicago was #1 in that study. But my point is BOTH of these colleges really like the academic high-flyers.
So I don’t think your hard work will somehow be wasted if you choose WUSTL, that is presumably a large part of why you got into both of these college! So, thanks to your hard work you have benefited so far from having the option to choose which college like this is actually best for you.
And then you will very likely further benefit from being well-prepared for college. Which is no joke at either of these colleges, they are full of very smart, hard-working kids, and you want to be well-prepared to keep up. And that will leave room for some fun too.