Emacs is just too old to be architected with security in mind. It's a great editor, but has baggage that IMHO can't be addressed on the spot.
Working on a codebase where you can't (heavily?) break things between any commit imposes such a slow pace that it's not completely unreasonable to start from the ground up and just study what made Emacs great and what didn't work too well.
It's surprising how long Emacs has been around and how good of an editor it is. It really makes rewrite attempts such a long stretch that it exhausts the motivation and time out of spirited folks that give it a go, but I think that given how complexity is being modularised and moved out (LSP, DAP, grammars) and newer languages make packaging easier that Emacs will eventually be replaced, definitely without covering everything it can do, but being strong at the average editing session.
Working on a codebase where you can't (heavily?) break things between any commit imposes such a slow pace that it's not completely unreasonable to start from the ground up and just study what made Emacs great and what didn't work too well.
It's surprising how long Emacs has been around and how good of an editor it is. It really makes rewrite attempts such a long stretch that it exhausts the motivation and time out of spirited folks that give it a go, but I think that given how complexity is being modularised and moved out (LSP, DAP, grammars) and newer languages make packaging easier that Emacs will eventually be replaced, definitely without covering everything it can do, but being strong at the average editing session.