None of them are.

I can't see how Boruto can be stronger than Mitsuki, Mitsuki has Snake Sage! Even though he hasn't quite used it yet besides showing it in the manga, he certainly does have it, putting him a mile ahead of Boruto. Mitsuki has the arsenal to many different wind jutsu along with many others. Boruto without his technology from Katasuke, he would be wooped, sure, he does have a mini rasengan, and some decent kunai skills he picked up from Sasuke. But he just can't win. Boruto does have the lightning and wind style too. If Boruto uses the technology from Katasuke, I can see this being a pretty even fight, with Mitsuki coming out on top at the end. But I just can't see Boruto winning.