Hello!
The worsen performance in late games can be atributed in character interactions tho I think the system is kinda bad implemented. In the modern age we sent messages through Discord and it reaches the other side of the planet literally in seconds but it is in the absence of this technology that we realize how dificult communication really is. Crusader Kings 3 gameplay takes place in medieval times so, the game must have some form of messengers which according to their skills may deliver messages and requests according to their skills that would define how fast a message could be delivered or how far they can travel and in an extend how many characters you can interact with.
Now I think that this should be applied to both landed and unladed characters, or at least pay to interact with a character. Like by stock, you from Ittaly can interact with Great Britain kingdoms, and have a response in a matter of days like your literally ordered something with UPS... soo with no planes and trucks I think that this is unrealistic. Their travel should be more or less like how you normally travel in the game so you may pay for them to have a safer route. Also I would like to have realistic estimates and not fictional about their speed and how far a messenger can travel.
What do you guys think? A bit of realism together with game performance?