I would say in tennis a "hot streak" from a lesser known player is less likely than in golf. In tennis basically all the grand slams of the last 11 years have been won by nadal, federer, djokovic, murray and wawrinka. Can the same be said for golf? And 49 out of the last 57 by just nadal federer and djokovic. They also won the last 10:
https://www.marca.com/en/more-sports/2019/06/09/5cfd3eb3e2704e319f8b45cf.html
And not only that: Very often in the finals they played against each other. Tennis is less random than golf in this regard.
But even if you consider the higher likelyhood of outsiders having hot streaks in golf, obviously strength of the best player competing against Jack/Tiger matters a lot in any case. Hot streaks from lesser knowns dont negate the fact that competition is on average higher for Tiger than it was for Jack