It's not just me. There's also some Zigs or Zags or something; pretty sure your list is missing several entries.

My pet theory, we can thank LSP for that, as it removed the major hurdle for any new editor project: the complexity of supporting modern programming languages and practices. Being able to offload most of that complexity to a language server (and most of the rest to tree-sitter) just about makes a new editor a viable side project.

As for motivation... I wonder how many of the new editors are a "let's rewrite it in Rust" thing?