The fact that there is no Yamal is not the reason for the defeat and draw in the last two matches by Barcelona. Revisit the matches and you will see that they had mistakes elsewhere, moreover Yamal is not Barcelona's most prolific scorer, he is an important player in the squad but not the main one. Real are actually on Barcelona's heels, even with their game in hand it's really hard to predict what the outcome will be at the end of the season.
Lamine Yamal is not the top scorer at the moment but even so, he is still very influential for Barcelona because his contribution to his teammates is very good and with the absence of the player, there must be a slight decline in Barcelona performance. And regarding Madrid, I agree with you that what Madrid is doing right now is just like a small problem that has happened in the past. As long as the points difference is not too far, Madrid can still catch up on the points to win the title this season.
Lamine Yamal has developed rapidly and become an important player in Barcelona main squad, Xavi gave him a chance, Hansi Flick managed to polish him to be better. His role has become more important over time, and the Barcelona front line looks more alive when Yamal is in the starting XI. Yamal is certain to be back in the match against Las Palmas, 6 goals and 8 assists are strong evidence that Hansi Flick really needs his role in the front line.
It is indeed difficult to predict where Barcelona will finish when the season ends, their position at the top of the standings is not completely safe from Real Madrid pursuit. If they avoid the storm of injuries, maybe Barcelona can maintain their position at the top of the standings until the end of the season. But the season is still too long, Real Madrid has the opportunity to overtake them in the future, therefore Hansi Flick and his players must always be vigilant.