Non professional opinion:
I think you should control your polycount. 150 000 verts is too much for just pull some parts from UV sphere. I think you should not put a high amout of geometry if your details doesn’t require such amount.
There is some tricks and you can see one in Sculpting the Wrangler cource. Kent separates his mesh into parts with grease cut and says it allows to handle higher polycount.
And yes, unfortunately, blender is not very good with high amount of geometry, ZBrush handle it better.
