Sessions - Please Change

Can someone attempt to explain what is the issue that is so complex about sessions and why is this taking so long to do in CI 3?

I truly do not mean to be sarcastic and my question is due to my lack of knowledge.

But what is it that CI 3 is attempting to do with sessions that is so different than what other frameworks do?

It certainly does not seem to take that long for other frameworks to come up with new versions and I guess they all have sessions.

Why can't we take what is being done elsewhere and incorporate it in CI 3?

Again I say this with all due respect.

Thanks