I have never seen my PhD mentor or postdoc mentor perform experiments by himself. Most established PIs do not do experiments by themselves any more, although I imagine they used to be great at it. They are too busy. I am not that too busy, and not established either, so of course I still do experiments by myself. However, I am getting busier with things other than experiments than when I started the lab for sure. I have more paper works, grant dues, committee duties, and so o