Remove parenting relationships?

Amazing, it's 2025 and it's still an issue, unfixed.

I found an easy way to accomplish this. Turns out copying frames only copies the frames themselves, and not the parenting relationships. So if you have a symbol inside which there exists a lot of parenting relationships between layers, you simply need to make a new document, paste your symbol into the new document, click into the symbol, select all frames across all layers and copy, then go back to your original symbol in the original document and replace all its frames by pasting in the copied version. The pasted frames may be exactly the same, but parenting relationships will all be gone across all pasted keyframes. 

In my case, I need to parent some layers for easy of classic tween animation. Once I've finished animating a parent layer (and its children layers have all followed the parent's motion), I insert keyframes in the children layers corresponding those in the parent layer, do the copy & paste process to remove parenting, and I end up with all children layers still animated according to the parent's motion, except there are no more parenting relationships! 

I just figured out that when you press on the child's parenting line, there is something pops out and choose remove parent. 

you can copy/paste:

objects (all or some) on stage

symbols in your library, 

timeline frames (all or some) from any symbol

layers (all or some) from any timeline

so if you want to unparent the objects on the timeline of ggp1.gp1.p1, copy the p1 layers (shift-click) and paste into a new symbol (eg p2). 

if you want to delete the children of gp1 (without deleting the p1 asset from your project), duplicate p1 and delete p1.