This heavily depends on your overall workflow and the outcome, you are aiming for.
I did a lot explainer straight in AE, including simple audio edits and SFX. Those animations didn't had a lot of videoedits and I always got a aproved storyboard by hand. The result was a final video following the storyboard 1 by 1 in a given resolution and image size. I kept everything in AE to be most flexible, don't need intermedia exports or any post animation effects. Keeping everthing in AE requires a strictly project structure with precomps hierachy. AE can handle a deep hierarchy better then long comps with a lot of layers.
If you plan to have a lot of edits, scene jumps, color grading, intensive audio edits and stuff like this, you may just create your animations in AE with handlelengths and do the editing in PR.
*Martin