The WWF may have been a lot different when the company went national in 1984 if Snuka's drug issue along with Argention's death never happened.
In 1983, Jimmy Snuka was voted most popular wrestling in Pro Wrestling Illustrated. Snuka had the look that Vince Jr. liked; the mystique, coolness and charisma that the fans flocked to, not to mention the sort of matches that most wanted to watch. Bob Backlund said that he was asked by Vince Sr. what he thought of Snuka, with the idea that Snuka may have what it took to become WWF champion. Minus the issues Snuka had, he basically ticked all the boxes that Vince McMahon Jr. looked for in a wrestler (draw, body, gimmick).
Tonga Kid was likely brought in to try to replace Snuka due to his increasingly lack of reliability. Tonga Kid was way too young to handle all the pressures of a full-time schedule of a major territory at that point of his career, which is why he didn't last long in a major territory (WWF, AWA/Pro Wrestling USA) until the Islanders team that was formed in 1986.
WWF tried to replace Snuka again with Sivi Afi, who became a jobber in short order when fans turned against another imitation.
When Snuka came back in the late 80's, it wasn't the same. Yeah it was the 'Superfly' but the magic was gone. Snuka was a shell of himself. It can be argued Snuka hadn't been the same since his feud with Roddy Piper which was 1984 pre-Wrestlemania 1. Maybe there is something to the story that Piper says about Snuka not being right after the coconut shot to the head on Piper's Pit. It could have been the loss of Nancy Argentino. Or it could have been a combination of the drugs, the wear and tear on the body and the murder accusations?
It's thought that Vince McMahon tried to sabotage both Snuka and Bob Backlund so that Hulk Hogan was the unquestioned top baby face despite fan reactions. Snuka, the most popular of the three, had his flame snuffed out little by little and Backlund left for the AWA /Pro Wrestling USA and retirement shortly after.
Both Vince Sr. and Vince Jr. thought a lot of Snuka, but when VKM took control of the company, he probably figured he could replace the top baby face character with anyone that looks similar and try to make it work. The fans know better. This seems to be a trap McMahon falls into time and time again; where McMahon feels fans connect more to the gimmick than the wrestler.