How old is too old ?....

Over the last year I've been updating my system,that was long over due.
Replaced a 16 year old cd player..mission DAD 7000
Hafler 110 pre..Blue Circle 3.1
Hafler DH 500...Bryston 4B ST( currently replacing again)
Various cables,too numerous to mention.
However I still have my old speakers Kef 104.2 and continue to like the sound.
These speakers are 16 years old.
My question...has technology marched on and left me and my Kefs behind?
I will replace at some time but for now I would like to keep these.
What improvement can I expect with newer speakers..a little ..alot....WOW...
Am I upgrading in the right order?
I've been told that all the upgrades ,to date,are wasted unless I replace the speakers ..VERY SOON.
Is a true statement?