AFAIU, LDK’s main target audience are wallet providers that want to add lightning functionality to their existing wallet software. In that situation, LDK handles all interactions with the Lightning Network, but the wallet developers need to bring-their-own-blockchain (e.g. Bitcoin Core) and need to handle their on-chain transactions themselves.

If you just want to run a Lightning Node, I don’t think that LDK by itself is what you are looking for.