The number of Cardano pools must never decrease

Cardano has a huge number of pools that are managed by independent entities. 

Some operators operate multiple pools. Only 2 operators have an approximate 10% share in the production of blocks. 

The third and other operators have less than a 4% share. There is currently debate in the Bitcoin community that 2 pools together have more than 51% share of block production. 

Namely Foundry USA and Antpool. 

According to some, this is reportedly not a threat to decentralization, as miners can supposedly delegate the hash rate elsewhere at any time. It's very dangerous not to see the tendency towards centralization as a problem, and to comfort ourselves with the argument that pool operators can't do anything without miners anyway.