Let's not forget there is a YUGE difference between the 2016 and 2020 situations. Obama WAS on his way out the door. The 2016 nomination was coming at the end of Obama's second term when there would absolutely be a different president in a few months (either Trump or Hillary). Also, the opposition party held the Senate in 2016 and the same party holds it in 2020. The Senate could have gone through the process and simply rejected Garland (and all subsequent nominees) in 2016. The effect would have been exactly the same as not taking up the nomination - the seat would be vacant until the new president is sworn in.