Lightning Network is a Layer 2. State channels also exist on top of Ethereum, such as Raiden Network and others[1].

The Eth core devs and users are more interested in rollups due to them being general-purpose[2], i.e. suitable for applications and smart contracts to build on top of (for e.g. Uniswap on a rollup via zkEVM[3]).

[1] https://ethereum.org/en/developers/docs/scaling/

[2] https://vitalik.ca/general/2021/01/05/rollup.html

[3] https://scroll.io/blog/zkEVM