These pools are not centralized because they store their block rewards in a custodial service, i know it sounds 'weird' that all 9 of them chose the same custodial service, Cobo, but it is not for this reason that they can be called centralized.
Pools are by definition centralized, it's a domain name, a person or a group running it, they make the decision, they make the calls.
What we have here is by no means decentralization, we have 9 businesses having the same custodian, mining directly to their partner, and if this deal was possible one might have to ask what else is going behind the scenes.
These big mining pools are the only ones that becomes centralized they have 47% of the total hash rate meaning it's still not centralized there are 53% of the total hashrate is still on decentralized pools and other miners can still mine on other pools if they don't want to mine on a centralized mining pool. ViaBTC and foundrydigital are not included on the list so they don't have full control of all pools yet you can also mine on your own and deploy your own pool if you have a mining farm.
You know too well that foundry is a closed pool, you can't just mine there without them approving you as a parent and with minimum hashrate requirements.
So the alternative to those is actually a bit worse ..