I'm not worried about his coup.
I'm worried that he's crossed the Rubicon to set a new precedent that the presidential transition process can be messed with for political reasons, and that losers don't have to concede after the race is called. This is a big step towards an eventual coup in a future election.
Further, he's set the Republican Party up for a "stab in the back" myth that Biden is illegitimate, which will haunt the entire Biden presidency.
Was you worried when Democrats and "deep state" were undermining Trump questioning his legitimacy etc? A rhetorical question. Obviously, undermining Orange Baad is equal to save democracy, undermining Biden is a coup 🧐!
Well technically, by "democracy" Hillary Clinton would have been in there, since she got more votes.