Imo its not about new technology but benefit. Its 250 euro for 5-10% performance. Maybe im missing something but i dont think its worth it
It is not about new technology. It is about the "current" technology AND how far that will carry you into the future.
No doubt, this is about predicting the future. But when you study the past, the future becomes pretty clear.
Let's say you buy a DDR4 platform today. That means you must buy an older, superseded technology motherboard that supports, what is becoming "legacy" DDR4. And of course, you must buy a CPU that same soon-to-be legacy, motherboard supports.
What if, in 2, 3 or even 5 years, you decide to add more RAM? Or upgrade to faster RAM? Will you be able to find new DDR4? Maybe not. Or let's say you want to upgrade your CPU. Will you be able to find one that is still supported by that "legacy" motherboard? Maybe not. So instead of allowing your computer to "evolve" in small, affordable steps that keep you current and carry you further into the future, you may be forced to buy all new again.
In the long run
, you end up spending more.
So yes, as a "tactical" short-term buy, going with DDR4 today will likely save you money today. But "strategically" you likely will end up spending more in the long run because you will be forced to upgrade the entire platform sooner.
If spending €250 more today saves me €500 (or considerably more!) down the road, if my budget allows, I will, without hesitation, spend that extra €250 today.
Don't forget the added three-fold, "warm fuzzy" factor. First, DDR5 offers better performance. Second, DDR5 is more efficient. And last but not least, third, if you go with DDR5, you will not look back with regrets wishing you had treated yourself and gone with the DDR5.