It's always been known that as a boxer ages the first thing to diminish is his speed / reflexes. Pacquiao at age 39 doesn't seem like he has lost a great deal of his speed. Although Lomachenko relies on a different form of speed than Pac-man, could it be possible that Loma holds majority of his speed for another 10 years?
The main difference is that Pacquiao rips off lightning fast combinations with power in each shot. Lomachenko throws his combinations and selectively puts power behind some shots. Lomachenko uses his combinations to befuddle and distract while Pacquiao makes every shot count. Prime Pacquiao is faster and more powerful.
I think that is clear that Lomachenko was created for boxing, he was teached since he was a kid and trained really hard. Pacquiao is a freak of nature, he is just fast, explosive and powerful in a way Lomachenko has never been.
Floyd is a combination of both, but more technically sound, better inside fighting and a better fighter overall.