The government wasn't overthrown, Hollie. It still stands. Biden is still president. Nothing illegal happened. There was no violence. The issue wasn't even a government one, but a DNC issue, where they worked out who their candidate would be.
Biden dropped out, just like Haley dropped out. He released his delegates to vote for Harris. Haley released her delegates to vote for Trump.
Nothing you've described matches the definition of 'coup' that you've offered. Nor does a single article you've cut and paste the URL for back your hysteric claims of a 'stalin level coup'.
Instead, some democrats expressed their concerns that Biden couldn't win. Biden dropped out because he felt it was in the best interests of the nation and the party.
How is that a 'coup'?