I wouldn't get hung up on the pool's hashrate. From a screenshot I had from August 2018 they had 256k+ active workers and 6.12 Eh/s. Currently 3.28 Eh/s and 93k+ active workers. Drop since then has largely been due to halving, difficulty, and profitability. People stopped mining because it's not profitable for most and it doesn't make sense to buy the latest gear.