I agree with you that Lazio would win against Juventus when they play on Saturday at Lazio's home. Since Juventus lost the Italy Serie A title race to Inter Milan, Juventus has not been consistent in the league, and because of that, AC Milan overtook Juventus to occupy the second position in the Italy Serie A table.
There is still no certainty before the match starts because when saying one club will win it is only based on the perspective we have but in the end there is still no certainty about it because looking at the records of the two clubs actually I think they still seem ordinary and there is nothing that can be used as a benchmark that they will win easily in the match later.
Juventus will lose Dusan who is definitely out due to his red card penalty but unfortunately they also have to lose Milik due to an injury that requires him to rest a few weeks which of course this is a loss and could have hampered Juventus for 3 points but on the other hand will this be well maximized by Lazio? The current conditions for Lazio are still uncertain and even their match record is not better than Juventus so even if they play home at this time there is no guarantee that in the end they can get 3 points in this match.