It would definitely accomplish something. It’s not clear if that would necessarily be a positive thing, but it would definitely be a pivotal moment in history. Even just the attempted assassination might eventually be seen as pivotal.
The right-wing is full of so many contradictory forces, and right now it’s only Trump’s cult of personality that’s holding them together. It seems very likely to me that post-Trump they’re going to fracture. If Trump becomes dictator he’ll probably groom Don Jr. to succeed him, and he’ll eliminate anybody who might question that decision. But, right now, Jr. is not in a position to take over from dad, so if Trump were no longer in the picture, there would be a power vacuum and massive infighting.
But, if the assassination attempt had succeeded, there would probably have been a lot more political killings, and just violence in general.