I do wish I’d fixed that collision, particularly since it ends up in the title card for the video that you see before you click play! In my defence, the version of the video that ended up online was the second take, and I had fixed the collision in the first take, and forgot to do so in the second.
Dorico doesn’t actually avoid collisions between dynamics and stems or notes that cross between staves. Although the specific case shown at the start of the Beethoven has an obvious solution to a human engraver — simply move the dynamic to the left — in the more general case, positioning dynamics when you have stems and beams between the staves is very much more complex, because you typically can’t move dynamics such that they don’t either collide with the beams or stems or move away from the notes to which they apply. Furthermore, Dorico won’t actually move dynamics left or right in order to resolve collisions: it will only move them up and down. The position of dynamics is carefully worked out, taking into account the rhythmic space, the note value, and the optical centre of the specific dynamic you’re using. We don’t want to then muck that up by moving it left or right.
In the end, those kinds of decisions are better left up to human judgement. Yes, in the case of the Beethoven example, it seems pretty clear that any human editor would move that dynamic to the left, but making Dorico do that in that situation but not do something stupid in another more complex situation is harder than it might seem.