Exactly, the competition ahead will be very tough, not only in La Liga, where Barcelona has a very solid squad and coach. But the competition in the UCL is also very tough, with PSG as champions this season and several top clubs now forming even stronger clubs.

So, indeed, Xabi must be able to fix this and find a more appropriate approach, not speculation that could be detrimental in decisive matches.

I read an interview with Luis Enrique regarding his response to Xabi, and here it is:

I think any club should be considered as a blessing if they get to know the weaknesses and the problems which cause them to fail. Like the whole debate over here is on the point that what and where the Real Madrid is needed to fix the things. Because without fixing the problems your way of success will remain blocked. So the team should focus on the defensive line and how they make it as strong as it should be. I think the strategy plays its important role to enhance the performance of the team. If you have good players but not good performance then things need to be settled down. And the lack of planning should be seen clearly over here. To avoid anymore chances of failure the team and coaches need to be on a page.

Well, this is one of the issues that has been a problem for Real Madrid since Toni Kroos retired from professional football. We've seen a decline, which initially didn't seem that significant. But over time, we've seen this problem escalate due to the lack of a solution and the lack of a replacement who can match Toni Kroos. Central midfielder is a position that sometimes doesn't attract much attention. However, this position is crucial because it's where creativity begins to build attacks and also from where the door to the defense can be opened or closed. The central midfielder is a position that is like controlling the game or implementing it so that strategies run according to the coach's instructions. Therefore, it really requires a player who is truly creative and really knows where to start an attack and the like. Toni Kroos used to be very reliable in this area. However, there hasn't been a replacement who is on par with him until now.

Real Madrid's defensive midfield and defense also deserve criticism. Opposition teams can always find gaps these days. This is also what allows PSG to penetrate Real Madrid's defense with relative ease. As for the attack, we know Real Madrid already has what they need. But again, no one has been able to pamper them with better passing. And I feel like Vini Jr. used to work harder before Mbappé arrived. I liked how he always managed to link up well with Jude Bellingham, who was sometimes used as a right winger, and even then, Bellingham was a very prolific goal-scoring player.

And there's some bad news about Jude Bellingham. He's set to miss the next few months after undergoing shoulder surgery. Hopefully, he'll recover quickly and return to the team in better form. I now understand why he didn't perform at his best in yesterday's match.

On the other hand, this is further proof that PSG are currently far superior to Real Madrid in terms of performance. PSG can put Real Madrid under pressure and make mistakes that lead to goals. Real Madrid certainly has good squad depth, but when the opposing team plays better, any strategy may be ineffective. We shouldn't just focus on how Real Madrid should play to win, while we forget how to appreciate the opposing team that has a better performance.

PSG are now in the final and need just one more win to complete their title quest. Luis Enrique and his team are in high spirits, but Chelsea certainly won't stand idly by and allow PSG to progress unabated. PSG may be the favorites in the final, but football is unpredictable.

That's right, Xabi Alonso hasn't found the right strategy to maximize his squad potential, and the defeat to PSG proved that. I think Xabi Alonso needs to focus more on improving his defense. Conceding four goals in one match indicates his defense is indeed very porous.
I think this is part of the risk when building a squad with a majority of attacking minded players, making the defensive line very vulnerable to conceding goals. Meanwhile, the three defender scheme doesn't seem to be effective, Xabi Alonso still needs to find the right strategy going forward.

When it comes to Madrid, they will always struggle when they meet a technical midfield and an attack that presses well and creates chances easily. That is why they had so many issues when  they faced Barcelona last season and why they couldn't win against Arsenal over both legs, and the same reason why they were humiliated against PSG last night.

Madrid's problem to me is not really the defence. The problem starts from the midfield to the attack The midfield doesn't know how to retain the ball and control the game. They don't have a player who can do that. That is why I laugh when I see people make fun of Pedri because it is because of players like pedri that a team can control the tempo of a game. PSG has that kind of player in Vitinha, Bayern have Kimmich. When you look at other top teams in the past, they all had that figure in midfield. Madrid had Kroos, but the mistake they made was replacing him with players who can do what he does. Both Belligham and Valvede can't do that. They can be very good players in other positions, but as controllers, they will fumble.

Then we talk about the attack. Vini and Mbappe are not players who can work hard off the ball. The first 2 goals of PSG yesterday came out of the hard work of Dembele. We've seen how hard Raphinha works off the ball for Barcelona. This is what modern football is, and if you're not ready for it, your defence and post will pay for it. 
IMO, Madrid's problem is not difficult to fix as long as the coach can identify it and make plans for it and make sure the players execute it the way he wants. If they can't do that, then its going to be another bad season.