One of the ways to test the story construction is to see if it would work in a different setting.
In this post, we take away a key feature of the series: the island.
The main characters never arrive on the island. There is no plane crash. Things play out in LA (like the sideways world view).
The island focus was on Jacob being a protector of the life force that could destroy the world if it fell into the wrong hands. We still don't know for sure what he was talking about. But if all life in the universe is made by a single energy spring in an Earth dimension in space-time, then it could be located anywhere.
The nomadic cult of The Others would be turned into what Dharma should have been: a layered R&D academic-military corporation charged with trying to a) find the source; b) capture the source; c) and weaponize the source. Who would not have bought into Ben being the ruthless CEO of Dharma?
Likewise, the rivalry with Widmore over the search and control of the power source would have been a more realistic and compelling fight than Widmore's return to the island and their short and bloody confrontation in the presence of Flocke.
Since the life force is a scientific property, Dharma and Widmore would need to recruit scientists, medical professionals and test subjects in order to research and development the energy. Jack and Juliet could have been recruited for their medical/research expertise. Widmore could have retained more unethical or risk takers like Dr. Chang, Daniel or even Keamy. It would be like two rival mining companies drilling on opposite ends of a mountain to reach the motherlode of gold.
What about the non-technical people in the series, like Kate and Sawyer. How would they get involved in this scientific show down? Well, it was past procedure to use criminals in medical experimentation and human trials. With Kate and Sawyer's criminal backgrounds, they could have made "deals" to lessen their sentences and be assigned to the R&D departments. Likewise, mental patients were unethically used as guinea pigs in drug experiments. People who could talk to the dead like Hurley and Miles could have been transferred to the R&D departments.
So we have these two rival companies sparring over the motherlode of life itself. But is that enough conflict? Perhaps, but like in the series, there is another element at play - - - the pseudo-religious, faith in humanity based players in Jacob. Even today, big pharma companies are going back to ancient civilizations to research their treatments and remedies to see if their crude medicines have any modern applications. Further, many religious orders kept alive the ancient secrets and knowledge during the Dark Ages. So, if we give Jacob and his followers like Dogen, Locke and Alpert a monastery setting as guardians of life source, then we have a three way battle for control. It could be like the Knights Templar guarding the Holy Grail.
The basic elements of the island story could have easily been ported to a modern, industrial park setting with probably more reasonable intrigue, corporate sabotage and spying, human manipulation and dangerous gambits than the generic jungle trek missions. And clearly, there would have been a single end game to the series: one of these three groups would be the victor and control the life spring. But the open question is who would be that group (and whether there would have been changed loyalties and new alliances to make it happen).
One result could be Dharma and Widmore destroying each other's plans with the help of the religious zealots. Or another result could be the test subjects could rebel and take control of the light source and use it to regain their freedom and purpose in life (in other words, becoming the new guardians of the life force).