Courtois is great. Arguably the best in the world overall and def top 5--probably after De Gea's world cup it pretty much settled it for them on where to go. However TC (also true for DDG) not ideal for their style and like any keeper can't paste over everything. Navas is very very good IMO. Liverpool did well to get Alisson early, and less than the reported fee for Kepa (crazy), and way way less than Oblak's release clause.
Chelsea has no choice in this one and I think it hurt them way more than it helps Madrid.