Update Renderer Bounding Volumes - Lower Game Performance

I was getting the lower performance of my game on desktop and mobile both.
So I have used a profiler to know the reason behind this but I can’t able to understand actually what is the problem!!!

If you check above image then you can see that updating renderer bounding volumes taking so much time so what is causing the problem?

Canvas Build Batches also showing many big spikes:

Try drawing objects out of their parents.