I don't claim the situation was optimal for Barcelona, it was not. I just say that comparatively a strikeforce of Messi, Griezmann and Dembele is way better than Benzema and two 19 year old Brazilians. So as long as you do things more or less well, the potential of a Barcelona squad in the league is way higher than anyone else, because in the league a good organization can restrict the rival's chances but if you don't have the quality upfront the opponent, no matter their position in the table, has good weapons to limit your attack and take points away from you with draws and narrow results like 0-1.
Also, if Ansu Fati gets injured at Barcelona you still have the goals. If Hazard gets injured (and he has been injured for two years now), you will a have holding midfielder as the second top scorer of your team.