That is a fair question and it's probably shared by many people. I agree those changing elements you mention would make racing more interesting.
But... most important in my opinion and many others is to get the cars feeling right and handling right. We would say, what is the point of having things that change your car when it never felt right in the first place?
LFS without the tyre updates is already an approximation of reality, good enough to enjoy, learn something about cars and do plenty of competitive racing. But there are situations where the car doesn't really do the right things. The response to some of the changes in setup and also finer points about what a car does when you turn the steering wheel and apply the throttle. It may sound fussy but these are the things you feel every second while racing. Personally I have found when testing for example an LX car around South City Chicase route, more excitement with the version I have, even got kind of hot and sweaty a few times just driving one car in practice mode as I started to drive several laps for no real reason. Getting hot and sweaty isn't necessarily a good thing in itself... But I took it as a good sign.
Anyway, even at that point, further research into the things I still knew were not finished, showed up more things and that's what brought me onto the more detailed study of carcass deformation. This year and a half of tyre model development really have been one thing leading to another, though as you know there were other things that took some of my time during that year and a half. So the tyre model updates are the results of several months but not as long as some people imagine.