Staked ETH derives profit from your own effort. You have to buy equipment (consumer-grade computer), pay for internet and energy costs to have it plugged and put your own effort in maintaining it online, operational and secure. This is basically a side-job for techies but a side-job in the end. Staked ETH rewards are thus not passive income and staked ETH is not a security. In a similar manner that rental income is taxed as income and a landowner that rents an appartment is not issuing an illegal security.

A different thing is what happens with a liquid staking token like stETH, a much better argument can be made that it quacks and walks like a security.