As always i spent the whole night figuring this out. For some reason the texture from the displacement bake (while in the solid tab with the texture setting enabled in the viewport shading) is shown completely different from the material preview tab. i figured this out when i continued the lesson and baked the next map from the level 2 to level 6 in the multires. As shown in the lesson i connected a color ramp node and there it was, all my detail captured in 4k. then i tested the first bake and again the texture was shown as expected. 
This is the first bake in shown in the solid tab. looks very different than the one shown in the lesson.

Same bake in the Material preview tab. looks fine, i didn’t have much pore depth to be shown in the first map.
Ok now the level 2 map in Solid tab, looks like no detail was even captured

And in the Material preview all my detail i shown just fine. and that’s why i thought that the bakes are falling. 
Now i have a really bad time figuring out how to bake the pointiness map. my pc has a 4070 with a i5 13600kf and 32gb ddr5 ram and blender crushed every time. i don’t know what to do it drives me crazy.