I think thismost recent Republican primary solidly proves the Republicans don’t run their party the way the Democrats run theirs, with no contestation. Indeed a lot of the media coverage of it was how they were in “open civil war”, while the Democrats were allegedly all proper and civil — and united. The leaks show this clearly to not be the case. Indeed there was plenty of smug commentary from the Democrat side how the Republican Party would be better able to fight Trump if they had used the same system superdelegate as the DNC. A system specifically and unabashedly designed to prevent the people from overruling the party elite.
Now unless you’ve got any evidence that the massive fight on the Republican side last year was all kayfabe, your assertion that they both operated the same is absurd. For all their many flaws, at least the Republican fight was transparent and even more democratic the the DNC one.