It doesn't look that close; the model of interaction seems to be completely different. twtxt is a command line tool with flat files and no obvious way of linking content, and logseq is an outliner with hierarchical files and bidirectional links created with wiki-like syntax.

Someone without advanced knowledge of the command line would not know how to start using twtxt, while using logseq is as simple as any plain text editor.

What do you see about twtxt that seems similar to you?

Logseq doesn't have "posts" as such, nor is there a protocol here for sharing. There's nothing graph related in twtxt. It also doesn't integrate with the personal knowledgebase people are already using. I'm not sure why twtxt would come to mind as similar.