For me there is something even worse with Diplomacy... it never feels like you are actually talking to someone, a personality, a alien avatar. It always feel likes we are just talking to an script "press this -> causes this" and not a dynamic dialog between races, with synergies and things the other side might find disgusting, strange or just plain misunderstandings that lead to situations you didn't expect.....
I always hate it when there is a "meter" that checks a number to decide whether you are allowed to do something or not. Diplomacy does not work like that in reality....
TLF does many things right when it comes to that but it also wouldn't really benefit from more immersion in these diplomacy windows we have, as we have so many choices there'd be no way to represent that otherwise. And we really do need to know what does what exactly how much in TLF too... but for a TBS 4X .. we have time, and diplomacy should be something that grows, that causes races to dynamically grow together or apart over time. With various benefits, events and interactions. (Basic things, like "School exchange programs" or "Private property ownership rights" that would slowly lead to a immigration of the other race/people to yours....