Nico Williams is still 22 years old, this is very good for the long term of the team and indeed in terms of individual quality Nico Williams is quite good, it's just that there is an added value when Nico Williams is paired with Yamal in the Spanish national team which makes the performance of both considered quite suitable but apart from that I like Nico Williams individually, he is a great player.
If Nico Williams comes I don't think anyone will be marginalized between Raphinha and Olmo because these three players will really help the team with the rotation that can be done by Hansi Flick and these three players can play in different positions, Olmo in the middle, Nico Williams on the wing and Rapihna can play a little up front so there is also a possibility that the three can play together.
It is obvious that Nico would be perfect for them, both a Catalan player AND also 22 years old and the Spanish teammate of Yamal, everything is like a dream, and he wants to play there too, so it works amazing for them. However, you can't just put Raphinha on bench, that is not how it works, he is a great player and he is doing a wonderful job and we should consider it being a lot better for them to sell him. If they can somehow get Nico, then they should get rid of Raphi so that he could go play somewhere.
Plus, as a team who has so much financial trouble, they can make at least 40-50 million from selling him, that's not really bad money and they can use that money to go buy Nico and while it may not cover all of it, it will cover most.