Usually a coup is counted as a success if the person executing it takes it remains in power.
Trump did not remain in power, and the attempt is counted as a failure.
It’s a clear sign that there’s danger to the democracy, but that doesn’t mean the coup didn’t fail or that the democracy has.
Hitler took power after a failed coup, but that doesn’t mean that the coup wasn’t a failure, since he didn’t take power as a result of the coup.