WHy did MS want Fallout and Elders Scrolls when they were making Avowed and Wasteland/The Outder Wolds? Because why not?
Well for one Fallout and Elder Scrolls are bigger. The opposite is true for Uncharted/Tomb Raider, Sony already has the bigger franchise.
The core issue probably isn't Tomb Raider. Square Enix likes to sell a studio with their IP. They probably sold for such a small amount because the western studios have had an incredibly hard time making money. The challenge to make Crystal Dynamics profitable was probably not worth even getting Tomb Raider. Even the studio that just launched a big Marvel game last year barely broke even.
I keep forgetting GP exists lol. In that case that just adds to why Sony would want TR. More games for their service.
Sony isn't investing in their service in any major sense the way that MS is. For MS it's their primary platform.