Here are two arguments that you have not refuted. The founders envisioned the electoral college as a means to ensure the powerful position of POTUS was elected by a widespread majority of the states. In 2016 Mrs. Clinton received more popular votes than Mr. Trump but Mr. Trump was the winner of many more counties than Mrs. Clinton. The electoral college vote for Mr. Trump reflected more widespread support.

With a national popular vote electing the POTUS the vote count of every state can become critical to the POTUS outcome. Consider the recounts and legal challenges that are going on now in states where the vote is close between Mr. Trump and Mr. Biden. If the national popular vote were close every state would endure recounts and legal challenges.