Why? BB30 is fraught with problems IME, all be it not as many now as the early days, however, BB30 still remains the answer to a problem that simple never existed.
I converted my BB30 bike to Hollowtech II after continuous creaking issues, and it's been perfect ever since.
If your BB shell is 68mm you can fit Hollowtech bearing cups and a compatible chainset, but you won't be able to fit BB30 as it requires a 30mm shell IIRC.