The Real Madrid squad is a good one and they are capable of beating any club in the UEFA Champions League this year. Just as you said, Real Madrid needs a good striker who will help them score goals in a difficult situation, and also make their games to be more enjoyable to watch.
I think it's not as easy as you say because this season there are many strong teams who are ready to compete strongly, such as PSG, Bayern Munich and Manchester City. So Real Madrid must be able to appear consistent when they face representatives from the Bundesliga like Bayern munich because if they are not in their best form then Bayern Munich will be able to beat them.
I think this season still has a long way to go and Real Madrid really needs quality strikers in their front line. Because if they only rely on Joselu it will definitely be quite bad for them. Ancelotti seems to need the right duel for Bellingham on Real Madrid front line this season. Indeed Bellingham is their top scorer this season but he is not a pure striker.
Real Madrid might still be able to overcome it if they play in La Liga, but in the Champions League, Real Madrid seems to be facing difficulties because the strong clubs like the ones you mentioned have better quality players than Real Madrid. They have strikers they can rely on, while Ancelotti only relies on Juselu. I don't think Juselu is good enough when compared to Haaland, Harry Kane and Mbappe, this is very different, but I think Anceloti already has a plan regarding this. Even though Real Madrid doesn't have a striker they can rely on, but Real Madrid can rely on Bellingham even though Bellingham is not a striker pure.
Real Madrid should have a pure striker but unfortunately Ancelotti has no intention of bringing in a new striker because Mbappe's arrival seems to be just a rumor, Ancelotti will rely on the current players with the tactics he has, I'm sure Anceloti knows what needs to be improved and Anceloti is very experienced so just trust Real Madrid to this coach.