Ronaldo jumping around and screaming on the touchline has nothing to do whatsoever with Portugal winning the Euros, and I'd go as far as to say that he made the team worse when he was on the pitch, not better. If anything, he held them back a bit.
No, Portugal won the Euros because it was a shit tournament and, honestly, has been for some time. This is due in part to the terrible way these things are designed, as well as football currently being a bit shit across Europe in general.