So im not sure about shows
But if we see time travel stuff they usually end in a loop, it's just how someone is going to explain their way around it
Few movies I can remember:
Donnie Darko
Interstellar
Predestination
And even Avengers endgame had their own logic with time and tech
So i feel dark should have at least put efforts to answer the questions they revolved whole of S1 for