It'll just have different design decisions and flaws. Expecting anything else is unrealistic. Bit-rot means that X isn't as well-suited to today's environment as we'd like, but I'm sure that some things in X that are regarded as mistakes now were trumpeted as great advancements when they were introduced. Similarly, Wayland will someday be in the same position.
That doesn't mean that it's not a net-positive to develop and start using it, of course.
> Bit-rot means that X isn't as well-suited to today's environment as we'd like, but I'm sure that some things in X that are regarded as mistakes now were trumpeted as great advancements when they were introduced.
Maybe they were great at the time. If you don't have enough memory to store every pixel of your screen, only storing properties of some basic geometric shapes seems to be a nice solution. If you have plenty of memory and want to control every pixel this becomes rather useless and even a burden.
That doesn't mean that it's not a net-positive to develop and start using it, of course.