Yes you are right about that but i think christiano ronaldo is an important person on real madrid, it's like he can to be a leader on real madrid and also can support their teammate on real madrid. Let's see what can Zidane do on the next matches without ronaldo, if he still can't figure it out, it will be a big problem.
football should be not an individual play but admitted or no sometimes there are the teams who too rely on the particular players such as Messi to Barcelona and Ronaldo to Real Madrid and if they're not played because got injury or suspension then the teams itself cannot playing well and usually they will lost and i think this is the cause for now why Real madrid still cannot showing the best performance yet because they still cannot figure out the players who equally to Ronaldo skill
Over reliance on a single players tends to be bad for every time. Look at when the MSN was at it's prime though Messi was the superior player, one can say that the team wasn't over dependent on him, there were times that Messi didn't play exceptionally well but the likes of Neymar and Suarez played their parts wonderfully and it all goes well for everyone. But with a one man team when the star player is stopped, the whole team crumbles. With the BBC we all know that only Cristiano Ronaldo has been playing well for some time now.
I agree with you, football is a team game, and not team should be dependent on any player, and to be honest I don't think Real Madrid is dependent on Ronaldo, or that Barcelona is dependent on Messi, but they do have tremendous value, and play a very important role on their team, so of course that if any of those key players misses a game, the team will resent a little from it. Since these top teams are so competitive, and they need to be at their highest level to win titles, the slightest decrease in quality can be deadly and that's why they seem to be so dependent on these key players.
Real Madrid will probably still win most of their games without Ronaldo, because they are a great team, but they will draw or lose a few because he wasn't there, and that will have a big impact on their overall performance, and there is nothing they can do about it.
So I don't think they are dependent on him, but if you lose as much as an inch on the level they compete, it makes a big difference.