The base protocol uses 32 ETH for technical reasons but yes, as you said, pools like RocketPool, Lido, etc along with exchanges like Coinbase, Kraken, and even everyday banks also allow staking any amount of ETH by anyone to take advantage of the stable staking returns. In a practical sense there's no barrier to staking ETH and it'll likely be the default way to hold ETH long term as a low risk savings vehicle.