Last month, Foundry USA coordinated 34% of the hash rate alone.

If we add Antpool, whose share is 18.2% of total hash rate, we have 52% of Bitcoin's global computational power in the hands of just two mining pools.

Stratum V2 is already implemented by Braiins Pool and is periodically tested by Foundry USA itself, but the vast majority of the hash rate is still coordinated by pools using Stratum V1.

https://bitcoinmagazine.com/business/stratum-v2-will-save-bitcoin-mining