Not only that, it will be a difficult season for Carlo Ancelloti and Real Madrid considering the squad depth and the unhappiness in their camp. With a decade long centre back pairing Varane and Ramos leaving to MUFC and PSG respectively; Casemiro wanting out of the team and won't renew; Misfiring strikers in Marianno and Jovic and an aging midfield pair.
What will happen to the Galacticos next season ?
It sounds so terrible for Real Madrid with the things I see in your post. It reminds me of how much that have been taken from the team that seems irreplaceable you know. At first, it was Ronaldo living for Juventus and ever since then, Real Madrid has been struggling without much of a success. Now, its Sergio Ramos and Varane. 2 center back that sure made a difference in the defense line of the team living for the league 1 and EPL respectively, living that positioned void of the kind of quality they delivered. Sergio Ramos position at most, being team captain and an on pitch coach to his team mates. Coupled with the fact that, he oftens knows when to step out and score that die minute needed goal for the team. Its tough to imagine a Real Madrid without him but, I guess the club will meet up with there challenge.
Alaba is definitely a very strong substitute. Similarly strong as Ramos when it comes to counter attacks. But Alaba also was a midfielder for quite some time and he can even contribute that quality as a defender. I would say that Alaba for Ramos isn't really that much of a loss in quality, if at all. What concerns me more about Real Madrid is the whole picture. No more superstars at all, no typical Real Madrid experience on the pitch, as you say an aging midfield. It is not going to be a good season for them I believe. What could give them a mental boost would be a transfer of someone like Mbappe.