Trickle down effect. The people who want ddr5 are settling on the higher end ddr4.
Two ram sticks are the best way to have the highest performance (2 16GB sticks are better than 4 8GB sticks). No one really wants to build a new PC with just 16GB of ram now, so people are looking for 32GB and 16GB sticks of ram. They also don't want the slower ram, so they're looking for 3,400+ mhz speed ram.
So for people wanting a gaming or video editing or ai system, no one wants the 8GB sticks of 2,400mhz ram sticks in your machines.
My generalizations are perfectly valid, because they're completely true. YOU are not most people, or most families. You are in a very large minority here, by being over 29, and being so young but had a grandpa who fought in the war. You're well below 5% out of the federation here.
*Final note to add: I specifically said (along with the original post) "grandma's". Not grandpa's. So your pawpaw fighting in WW2 isn't any validation as a sound argument. An old man will marry and have kids with a young woman. It seldom goes the other way around.