What value is the secondary market to them? Or allowing their players to "cash out"?

They can take a cut of every secondary market transaction and players need to be able to cash out for a secondary market to make sense. The main reason for not doing that centrally is it becomes an attractive means of money laundering which Valve found out with their skins. Second Life also had this problem and IIRC a third party company handles all their game related banking business as a result.

Note I’m not saying this is a good thing and I think all the entities involved should have the same regulatory responsibility but you can see the greasy cogs whirring in some executives brain.

How does it being decentralized make it unattractive for money laundering?

It doesn’t. Crypto is famously massively popular for money laundering. It just makes it not Ubisoft’s problem in the same way Valve farmed out the risk and responsibility to third party skin sites. Similarly Second Life dealt with this more ethically by engaging a partner to deal with the regulatory side of things

It’s also not a claim I made so I’m not sure why you addressed that question to me.

I addressed the question to you because I thought that was what you were saying: that somehow the involvement of a decentralized ledger made money laundering less attractive. Your description of the actual reasoning, that it shifts the burden of responsibility, makes a lot more sense.

In which case I apologise for not being clearer the first time.