The whole game doesn't revolve around that. In fact, it wasn't considered necessary for that mechanic to be functioning despite them deciding it was ready for Early Access. They only recently added visual effects as a result from aging. Others have claimed they've waited past 100 years without their character dying. The game can be played without it, obviously.
No other Mount & Blade game made characters have a mandatory expiration date. They didn't force players to re-level an heir to continue a playthrough. That legacy feature should be an option out of the box.
So which is it? The mandatory aging is a core component of the game, and significantly factors into the entire experience; or that the aging and heir system is barely an issue and unnoticeable for you?